How to disable Crossfire? What is Crossfire? How to disable Sli Crossfire? Crossfire connection. Myths about using Dual Graphics mode to increase graphics performance What is crossfire support on the motherboard

“The life of trade and the death of traders” - this is what Bernard Shaw said about it. And he spoke about competition, without which a market economy is impossible.

In a recent review, we looked at NVIDIA SLI technology. As noted at the beginning of that article, we examined the first technology on the modern graphics market for parallel operation of several video cards in one gaming scene. And since there is the first, it means there will be a second, since competing companies cannot allow NVIDIA to monopolize the market in this area. As one would expect, the main competitor, the Canadian company ATI, put forward its counterweight to SLI in the form of its own CrossFire technology (the company is now owned by AMD, but the CrossFire brand has been retained in the form of ATI CrossFireX).

Development history and key features

The technology was announced at the international exhibition Computex 2005 in Taiwan.

So, ATI CrossFire technology was designed to enable the creation of very high-performance gaming systems. Let us outline the main tasks that ATI engineers set for themselves: first of all, to maximize system performance in 3D applications, as well as improve image quality. At the same time, there was a need to maintain compatibility with all games and cover a wide range of graphics card models to work in the CrossFire system. The Canadians tried to use the positive experience from their past similar projects.

Let's remember, for example, ATI's first development in the field of multi-chip solutions - the ATI Rage Fury MAXX card:

In 1999, several manufacturers released new generation video cards. NVIDIA even did this twice: in the spring Riva TNT2, and in the fall - a completely new product GeForce 256. But ATI, unfortunately, apart from the fact that it belatedly offered RAGE 128 and announced an improved version of this chip RAGE 128 PRO, nothing sensational and revolutionary didn't. However, there are methods to improve your product without creating a new video chip. Once upon a time, 3dfx paved this path, providing Voodoo2 with the ability to work in tandem with the same video card. We are talking about the well-known SLI (Scan Line Interleave) technology. This technology allows you to use two cards on the Voodoo2 chip or just two Voodoo2 chips on one board to render the game simultaneously. Each of the Voodoo2-based cards in this case calculates either even or odd lines of the frame displayed on the screen, as a result of which the performance of the video subsystem increased by more than one and a half times.

ATI also used a similar idea, unable to compete with new solutions from NVIDIA. As a solution, a technology codenamed Aurora was proposed, which later received the name MAXX (Multiple ASIC Technology). MAXX technology is a pure software solution that allows you to use two GPUs to do a shared job. In fact, the idea of parallel data processing is being realized. Each of the GPUs completely forms one frame, and then the finished frames are displayed one by one on the monitor. The technology that allows two graphics chips installed on the same card to alternately display finished image frames on the screen is called Alternate Frame Rendering (AFR).

And so, presenting a new implementation of the idea of parallel rendering of a 3D scene in 2005, we had to recall all the existing developments, improve them and supplement them with new capabilities. In addition, the shortcomings of competing solutions from the American company NVIDIA were taken into account.

let's consider key differences ATI CrossFire from NVIDIA SLI. Let us immediately make a reservation that these differences took place in the past and are given only for historical reference and to reflect the progress of development of both technologies.

The most important difference between ATI technology was that in order to create a combination of two video cards, they must be of the same series, but not necessarily the same model, while in SLI technology both video cards had to be absolutely identical, almost up to version BIOS firmware. This was extremely important, since various combinations are possible for Radeon cards, for example, X1600 PRO and X1650 XT, which gave users greater freedom of choice when upgrading.

To date, this advantage over SLI has been retained. Radeon HD3800 and HD4800 series video cards “get along” well in one system in various combinations. Moreover, both within the line (HD3850+HD3870) and between generations (HD3870+HD4850). Although the latter is not confirmed by the official compatibility table:

ATI engineers called the second significant advantage of CrossFire over SLI the independence of the technology from driver optimization. However, we waited for what was promised for more than three years (since May 31, 2005, when the official worldwide announcement of ATI CrossFire technology took place) and still did not arrive. According to the developers, their technology should work with all existing games, even those released before its implementation.

With game support, CrossFire is doing a little better than SLI, but, as practice shows, even today there are games that in no way respond to the appearance of a second video card in the system. It all comes down to the same driver optimization that users hate. We will look at game compatibility and performance gains later in this article.

But it was not without its drawbacks. In its original form, ATI CrossFire technology required the presence of a so-called Master card. Such cards had the prefix CrossFire Edition in their names. They are equipped with an overlay chip that receives information from the slave card and combines it pixel-by-pixel with the master card.

On top is the CrossFire Edition X850XT card, and below is the standard X850XT. Pay attention to the overlay chip located under the transparent cooler casing.

The two cards are connected using an external cable that connects the DVI output of a regular card to a special DMS connector on the CrossFire Edition card. And the partially processed frame from the first card is sent via DVI to the DMS input of the CrossFire Edition card. As a result, the work of the two video chips is summarized in the Compositing Engine chip.

This approach slightly restrained the spread of the technology, since Master cards were not as widespread in retail sales as their regular variants.

As noted above, this method of organizing a combination of two video cards is already outdated. Today, combining two or more video cards in CrossFire mode, as with SLI technology, requires the use of special connecting bridges.

The fact that both competing companies chose this particular hardware method of organizing the connection once again confirms its maximum efficiency and practicality. Consequently, CrossFire Edition video cards left store shelves forever.

An important aspect in promoting CrossFire technology to the market is that it is supported not only by AMD’s own chipsets, but also by the most popular chipsets from Intel, although this support is implemented on program level. And with the advent of the P45 Express logic set, the technology has received great potential for use in the “Performance” class. The fact is that as the performance of video cards increases, the load on the PCI-e bus also increases, which should ensure data exchange between motherboard and a video card. And, if in the case of one video card PCI-e bus has 16 lanes, the so-called PCI-e x16, then in CrossFire mode mid-level motherboards can only provide PCI-e x8, which is clearly not enough for modern video cards. Starting with the P45 Express chipset, mid-range motherboards have PCI-e 2.0 support throughput twice as high as version 1.0a. Previously, such a standard was only available on motherboards in the highest price range.

Imaging algorithms

Dividing the screen into several non-overlapping zones (Scissor, also known as Slicing).

This mode cannot be called new - it is what NVIDIA SLI uses. Here the top of the frame is shown by one card and the bottom by another. Interestingly, the border of the zones does not have to run in the middle of the frame and can be selected dynamically, based on the complexity of a particular part of the image - roughly speaking, there may be fewer objects (the sky) in the upper half than at the bottom, and then one of the accelerators will be idle, which can be compensated by increasing his area of responsibility. The task of such dynamic balancing is non-trivial and requires scene analysis, which is not always convenient.

Advantages of the method:

divides both geometric and pixel load;
high degree of asynchronous operation of video chips;
the accelerator has complete control over its reporting area of the result image.

Disadvantages of the method:

requires balancing of zones on the fly to evenly distribute the load;
there may be problems with smoothing at the junction of zones;
requires significant intervention in the driver and therefore there is a high probability of unexpected and incorrect operation of some applications.

SuperTiling mode - checkerboard alternation of calculated pixels

IN this mode the frame is divided into blocks (also called “quads”). This results in a total of 256 blocks per frame. Even blocks are calculated by one card, and odd blocks by another.

In principle, using this mode you can display all applications and games. ATI has set this mode as the default for 3D games. However, despite all the improvements, there are also negative features. The fact is that, despite each card displaying half of the image, the geometry has to be fully calculated on both cards. As a result, productivity growth is not what it could be. However, even with such shortcomings, modern and future games that heavily use pixel shaders will provide excellent performance in this mode. In general, the more the game uses shaders, the greater the increase will be in a given CrossFire mode.

Advantages of the method:

divides the pixel load exactly equally;
very precise load balancing between video chips;
can be used for new full-screen anti-aliasing techniques;
easy to use for applications and requires almost no modification of drivers, there is little chance of applications not working correctly.

Disadvantages of the method:

does not divide the geometric load and therefore requires a significant margin in geometric performance;
requires sufficiently synchronous operation of video cards and, accordingly, their maximum identity.

Alternate Frame Rendering

AFR mode is the fastest - in it, cards output frames one by one. Let's say the first map displays all odd scenes, and the second - all even ones. Unlike SuperTiling and Scissor modes, where both cards have to calculate the geometry for each scene, AFR mode allows each card to only do half the work because each map calculates geometry and shading only for its frames.

Advantages of the method:

divides both the pixel and geometric load, and the geometry is not duplicated on the bus - different video cards receive different sets of data;
the video card is fully responsible for its frame, no traces of joining, even in the case of complex processing, no restrictions on the method of constructing the frame.

Disadvantages of the method:

uneven frame rotation and load distribution;
Efficiency highly depends on the CPU and system, as well as on the nature of the scene and falls with increasing frames per second;
problem with a significant delay between the frame that is shown to us and the frame that is in this moment under construction.

The last disadvantage of this method does not allow it to gain global recognition among users and, in some way, slows down the spread of the entire multi-GPU technology as a whole (both SLI and CrossFire). The fact is that this image output method sometimes produces the effect of “microlags” - small jerks in games that do not depend on the load and speed of your system.

SuperAA mode

It is obvious that the greatest increase in speed from using CrossFire will be obtained by games, especially those that load the computer’s graphics subsystem. But what if one video card can handle the game just fine? What to do with the second one?

Especially for such cases, CrossFire has the ability to work to improve picture quality - the Super AA mode was developed for this purpose. Thus, gamers can take advantage of the potential power of CrossFire by using a new full-screen anti-aliasing method. With its help you can get the highest picture quality, which is not available on single video cards.

ATI DPP(PhysX)

Also, in March 2006, ATI introduced support for hardware physics acceleration with its video cards for games optimized for the Havok FX engine.

It was stated that acceleration of physics calculations will be supported by Radeon X1000 series graphics cards, and asymmetric configurations will also be supported, for example CrossFire for 3D rendering and an additional accelerator for physics calculations.

In addition, the possibility of using two different video cards for calculating physics is stated. Unfortunately, the possibility of simultaneously using the resources of a powerful GPU for graphics and physics was not announced, as previously expected.

For GPU processing of physics, ATI plans to use a technology it calls DPP (data parallel processing), which allows a common set of instructions to be applied simultaneously to a large array of source data.

It was stated that the performance of ATI's solution would be superior to dedicated PhysX boards in many cases. Below are the proposed applications of the GPU as a physical accelerator.

Unfortunately, specific deadlines for the implementation of ATI physics acceleration software and hardware have not yet been announced; they will probably be announced in the near future, given NVIDIA's breakthrough in this direction with NVIDIA PhysX technology.

From history to modern times

To build a computer based on CrossFire you must have:

motherboard with two or more connectors PCI Express x16 with AMD or Intel chipset of certain models;
powerful power supply;
video cards with CrossFire support.

A CrossFire system can be organized in two ways:

Internal connection - video cards are connected via a flexible bridge. The driver determines which of them will be the master card.
Software method - video cards are not connected in any way, data is exchanged via the PCI Express x16 bus, and their interaction is implemented using drivers. Disadvantage this method there are losses in productivity of up to 10-15% compared to the first method mentioned above.

As you may have guessed, software method It is used extremely rarely and mainly on not the newest low-power cards. Regarding the bridge connection, be careful. Unlike NVIDIA SLI, 2 bridges are used here and they must be connected correctly, usually on the side of the primary card (the monitor is connected to it) the bridge is marked with a smaller index, and on the slave side with a larger index, for example, “J1A” “J2A” or “J2” and “J3”, although other more or less understandable designations are also possible. Otherwise, the driver will not recognize the installed combination of video cards and will ask you to change the bridge configuration on the corresponding Catalyst Control Center page.

This is what the various options for connecting bridges for CrossFire look like.

CrossFire is enabled quite simply by checking the box in the Catalyst Control Center menu.

Triple CrossFire and QUAD CrossFireX

With the release of drivers version 8.3, ATI officially announced the availability of QUAD CrossFireX technology. However, it is only available for video cards of the HD 3800 generation and higher.

The word QUAD does not mean that combinations of only four video cards are possible. The same technology also includes Triple CrossFire - a combination of three video cards. What’s interesting is that there can physically be two video cards, but three video chips are used. For those who didn’t guess, we’ll explain - in this case, a combination of a regular video card and a video card with the suffix “X2” is used, which has 2 video chips. Here is an example of two video cards Radeon HD 3870 and HD 3870X2 in Triple CrossFire mode.

And here is the result of their joint activities using the example of the game S.T.A.L.K.E.R.: Shadow of Chernobyl.

As you can see, the game responds favorably to the addition of a third video chip. The performance increase of two HD 3870 video chips compared to one is 85%, which is very good. But adding a third accelerator increases performance by another 33%, which is also quite good.

The QUAD mode is activated in two ways: the first is by installing four video cards in a special motherboard based on the AMD chipset, the second is by installing two video cards with the “X2” suffix in any one that supports CrossFire mode. As practice shows, the first method is used extremely rarely due to the small number of motherboards for 4 video cards and the large number of problems with their connection. Much simpler and more expedient method number two. It’s clear that “X2” video cards belong to the TOP solutions, and a combination of two such video cards is even more so.

However, in this way we will get unprecedented video subsystem performance.

It becomes obvious that for such video cards, motherboard support for the PCI-e 2.0 x16 standard is not just desirable, but mandatory.

Note that the Radeon HD 3870X2 video cards, which are actually a CrossFire implementation of a pair of GPUs on one video card, used a switching chip that was far from perfect. Not only did it limit the video card to only support PCI-e 1.0a, but it also had high latency. But progress does not stand still and, starting with the Rdeon HD 4870X2 line, a new switching chip is used that is devoid of these shortcomings. Now the internal organization of CrossFire in the video card has become much better, as well as the interaction of the video card with the motherboard, now via the PCI-e 2.0 interface.

The path of CrossFire technology to the masses has been so long and thorny. What does it represent today? And today it is a rapidly developing technology, support for which is widespread thanks to Intel and AMD chipsets. The uniqueness of the technology is its flexibility and the ability to build on various motherboards and processors, using Intel processors if you are using a motherboard Intel chipset or using AMD processors if you use a motherboard based on an AMD chipset, in any case, users have a wide choice of components.

AMD, which suffered a fiasco during the confrontation between Radeon HD 2000 (HD 3000) and GeForse 8 generation video cards, in the new Radeon HD 4000 line has set a course for promoting its products not in the TOP league, but in the middle (middle) and so-called productive ( Performance) segments. In view of this, having a combination of two video cards of average cost often turns out to be cheaper than buying TOP competitor products.

Pay attention to the fourth line from the top - this is the HD4870 video card in CrossFire. A very good result, considering the recommended cost of each card. However, this is just a synthetic test, albeit a very popular one, but it shows the potential of the technology when maximally optimized for the game. If you analyze the graph, you can see that the mid-segment video cards of the previous generation compete quite well with the “top” modern cards, but of course not alone.

ATI Hybrid CrossFireX. This technology is similar GeForce Boost.

Like the competing Californian company, it is designed to combine the power of a video chip built into the motherboard and a discrete video card.

To activate this technology, you will need a motherboard with a set of system logic from the AMD 780 line.

It is logical that using a video card more powerful than the Radeon HD 3470 is not advisable.

Much more interesting is the use of this technology in laptops, where in addition an idea similar to HybridPower is implemented (it’s a pity that this function is not available on desktop systems).

Now, in laptops based on the AMD 780 chipset, it is possible to combine the graphic power of a discrete video chip with long-lasting battery life, since the discrete chip simply turns off when there is no load.

Using hybrid graphics from AMD gives the user complete and easy control over image output.

We have already examined the performance of such a solution in one of our reviews. Let's remember the results...

...and conclusions:

“As a result, from the graphs we see that the performance of the “hybrid” graphics system, as well as a separate integrated core, strongly depends on the speed of exchange with memory, which is carried out by the processor via the HyperTransport bus. Therefore, Phenom processors have a certain advantage, but there is not much difference from using a triple or quad-core processor.

Even if the Hybrid CrossFire system were able to catch up with the NVIDIA GeForce 8500GT DDR3 Sonic, then from the point of view of economy this option would be questionable, since the cost of more powerful processors is an order of magnitude more expensive than video cards. Therefore, the technology of combining an external video card with integrated graphics will be of more interest to users who usually use image output on three or four monitors, and sometimes they need to work with 3D.”

Practical use

We have already tested Radeon video cards of various price ranges in CrossFire combination. Let's try to analyze these results and draw a conclusion about the feasibility of using this technology and its competitiveness.

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“The life of trade and the death of traders” - this is what Bernard Shaw said about it. And he spoke about competition, without which a market economy is impossible.

Development history and key features

The technology was announced at the international exhibition Computex 2005 in Taiwan.

From history to modern times

To build a computer based on CrossFire you must have:

a motherboard with two or more PCI Express x16 slots with an AMD or Intel chipset of certain models;
powerful power supply;
video cards with CrossFire support.

A CrossFire system can be organized in two ways:

Internal connection - video cards are connected via a flexible bridge. The driver determines which of them will be the master card.
Software method - video cards are not connected in any way, data is exchanged via the PCI Express x16 bus, and their interaction is implemented using drivers. The disadvantage of this method is the loss in productivity up to 10-15% compared to the first method mentioned above.

As you may have guessed, the software method is used extremely rarely and mainly on not the newest low-power cards. Regarding the bridge connection, be careful. Unlike NVIDIA SLI, 2 bridges are used here and they must be connected correctly, usually on the side of the primary card (the monitor is connected to it) the bridge is marked with a smaller index, and on the slave side with a larger index, for example, “J1A” “J2A” or “J2” and “J3”, although other more or less understandable designations are also possible. Otherwise, the driver will not recognize the installed combination of video cards and will ask you to change the bridge configuration on the corresponding Catalyst Control Center page.

This is what the various options for connecting bridges for CrossFire look like.

CrossFire is enabled quite simply by checking the box in the Catalyst Control Center menu.

Triple CrossFire and QUAD CrossFireX

With the release of drivers version 8.3, ATI officially announced the availability of QUAD CrossFireX technology. However, it is only available for video cards of the HD 3800 generation and higher.

And here is the result of their joint activities using the example of the game S.T.A.L.K.E.R.: Shadow of Chernobyl.

However, in this way we will get unprecedented video subsystem performance.

It becomes obvious that for such video cards, motherboard support for the PCI-e 2.0 x16 standard is not just desirable, but mandatory.

The path of CrossFire technology to the masses has been so long and thorny. What does it represent today? And today it is a rapidly developing technology, support for which is widespread thanks to Intel and AMD chipsets. The uniqueness of the technology is its flexibility and the ability to be built on various motherboards and processors, using Intel processors if a motherboard on an Intel chipset is used, or using AMD processors if a motherboard on an AMD chipset is used - in any case, users have a wide choice of components.

AMD, which suffered a fiasco during the confrontation between Radeon HD 2000 (HD 3000) and GeForse 8 generation video cards, in the new Radeon HD 4000 line has set a course for promoting its products not in the TOP league, but in the middle (middle) and so-called productive ( Performance) segments. In view of this, having a bundle of two medium-priced video cards is often more profitable than buying a competitor’s TOP products.

ATI Hybrid CrossFireX. This technology is similar GeForce Boost.

Like the competing Californian company, it is designed to combine the power of a video chip built into the motherboard and a discrete video card.

To activate this technology, you will need a motherboard with a set of system logic from the AMD 780 line.

It is logical that using a video card more powerful than the Radeon HD 3470 is not advisable.

Much more interesting is the use of this technology in laptops, where in addition an idea similar to HybridPower is implemented (it’s a pity that this function is not available on desktop systems).

Using hybrid graphics from AMD gives the user complete and easy control over image output.

We have already examined the performance of such a solution in one of our reviews. Let's remember the results...

...and conclusions:

“As a result, from the graphs we see that the performance of a “hybrid” graphics system, as well as a separate integrated core, strongly depends on the speed of exchange with memory, which is carried out by the processor via the HyperTransport bus. Therefore, Phenom processors have a certain advantage, but there is not much difference from using a triple or quad-core processor.

Practical use

AMD CrossFire technology accelerates graphics quality and performance by combining the processing power of multiple GPUs.

With AMD CrossFire technology, two or more discrete graphics cards can be configured to work together. You can also configure discrete GPUs to work alongside integrated GPUs using AMD Radeon™ Dual Graphics Technology. AMD Radeon Dual Graphics technology is based on AMD CrossFire technology and is only available on AMD APU-based systems.

Before you enable and configure AMD CrossFire technology, you must run the AMD CrossFire setup, which may require connecting a pair of video cards using an AMD CrossFire bridging cable. For more information about installing AMD CrossFire graphics cards, see your graphics card's user manual.

With AMD CrossFire support enabled, one GPU functions as the primary processor. Subsequently, graphics rendering tasks are distributed between this GPU and other processors to speed up image rendering on a separate display connected to the main GPU. Additional displays can be connected to the main GPU if it is running in extended desktop mode.

Note: If AMD CrossFire support is enabled or disabled, the Control Center application automatically restarts. AMD CrossFire is designed for applications running in full-screen mode. Displays not connected to host GPUs in an AMD CrossFire configuration are automatically disabled. For some configurations, you can optionally unlock support for displays connected to auxiliary GPUs.

Availability of AMD CrossFire pages and options may vary depending on specific graphics cards. The layout of the AMD CrossFire pages also depends on the currently used view:

Standard view - AMD CrossFire page is in groups Performance And Games > Performance. If you are using an AMD FirePro™ graphics card, the page is in groups Performance And AMD FirePro > Performance.
Advanced view - AMD CrossFire page is in groups Performance and Games. If you are using an AMD FirePro graphics card, the page is in groups Performance and AMD FirePro.

GPUs in AMD CrossFireX and AMD Radeon™ Dual Graphics configurations work together using one of four graphics rendering modes: Mosaic, Scissor Mode, Frame Alternate Rendering, and Super Anti-Aliasing.

The first three modes are focused on performance, while the super smoothing mode is focused on quality. Each mode uses a different way to distribute the workload across multiple GPUs when rendering 3D images. The AMD Catalyst™ display driver automatically selects the most optimal of three operating modes when launching a 3D application.

Tip: You can also improve image quality by selecting the super anti-aliasing mode (levels above 6×).

Mosaic In this mode, each processed frame is divided into a number of tiles arranged in a checkerboard pattern so that each of the two GPUs processes half of the tiles. Each tile is a 32x32 pixel square, so this method provides good workload distribution between GPUs, regardless of the rendered image displayed on the display, and without wasting software resources.

The advantage of mosaic mode is its ability to work with almost any 3D application. However, there are a small number of applications where tiled workload distribution does not provide optimal performance. In these special cases, the scissor mode can be used. Scissor Mode In this mode, each frame is divided into two sections, each of which is processed by one GPU. The ideal configuration is determined automatically for each application.

Although scissor mode is generally a less efficient way to distribute workload than mosaic mode, it can be more effective in some cases. This mode is supported by AMD CrossFireX technology for maximum compatibility and performance. Alternate Frame Rendering (AFR) In this mode, all even frames are rendered on one GPU, while all odd frames are rendered on another GPU. The rendered frames are sent from both GPUs to the compositing engine on the AMD CrossFireX Edition card, which then delivers them to the display. By allowing both GPUs to operate independently, AFR mode maximizes the performance of all available modes. This mode is also the only mode that allows you to simultaneously use all the processing power of both GPUs for vertex processing.

The main limitation of this mode is that it cannot be used in applications in which the appearance of the current frame depends on the data generated in previous frames, since the AFR mode involves the formation of successive frames on different GPUs. In such cases, use mosaic mode or scissor mode instead. Super Anti-Aliasing Anti-aliasing is a rendering technique designed to remove jagged edges, flicker, and pixelation that often occur in rendered 3D images. Instead of simply determining the color displayed for each pixel on the screen by sampling from one location at the center of the pixel, antialiasing takes samples at different locations on each pixel and mixes the resulting results to create the final color.

Most AMD GPUs use a technique known as multi-sample anti-aliasing (MSAA). This method samples 2, 4, or 6 programmable locations in each pixel and applies gamma-corrected blending of the samples to produce high-quality smooth polygon edges. The new AMD CrossFireX Super Anti-Aliasing mode leverages the GPU's programmable sampling capabilities to provide higher quality anti-aliasing on AMD CrossFireX systems.

In this case, each GPU renders the same frame with anti-aliasing enabled, but each GPU samples from a different location. Once both frame renderings are complete, the results are mixed in the AMD CrossFireX compositing engine. The resulting image is created from twice as many samples, so 4x and 6x antialiasing become 8x and 12x antialiasing, respectively.

Some textures, especially those with transparent areas, may exhibit aliasing that MSAA cannot correct. In these cases, another type of anti-aliasing called low-resolution anti-aliasing (SSAA) can be useful because it affects every pixel in the image. Although this process is typically slower than MSAA, the processing power of multiple GPUs can provide the ability to practical application SSAA.

When using SSAA, it first renders the scene at a higher resolution than the output resolution to the display, and then forces the resolution downsampling to match the display's resolution. This approach usually has two main drawbacks: it requires processing many more pixels than usual, which can have a big impact on performance, and it also results in the use of ordered lattice sampling, which is poorly suited for smoothing some types of jagged edges. AMD CrossFireX super anti-aliasing eliminates both of these shortcomings. This uses a second GPU to render the extra pixels needed for each frame, so there is little or no performance impact. It can also use a more efficient sampling model to provide better anti-aliasing of near-horizontal and near-vertical edges, resulting in higher overall image quality.

The two super anti-aliasing modes use a combination of MSAA and SSAA techniques to provide maximum quality Images. These modes not only use different multisampling locations for each GPU, but also slightly shift the pixel centers. Essentially, each GPU renders the image from different viewpoints spaced about half a pixel apart. The 10x and 14x super anti-aliasing modes work this way, combining 2x SSAA with 4x and 6x MSAA, respectively.

Both of these modes work in conjunction with anisotropic filtering (AF).

Users can enable super anti-aliasing modes using the Control Center app.

Note: Enabling super anti-aliasing modes (×8, ×10, ×12, ×14) disables multi-GPU (graphics processing unit) rendering, which is designed to improve performance to provide higher image quality.

Configuring AMD CrossFireX™ Hardware Settings

Use the AMD CrossFireX page to enable and configure AMD CrossFireX configurations that use AMD CrossFireX bridging cables. When AMD CrossFireX support is enabled, 3D games and applications automatically use AMD CrossFireX technology if the driver determines that using it is the optimal solution.

You can also configure super anti-aliasing mode for AMD CrossFireX using the 3D pages in the Control Center app.

Enabling AMD CrossFireX™

- Standard view - Performance And Games > Gaming performance.
- Expanded view - Performance and Games.
- Standard view - Performance And AMD FirePro > Graphics Performance.
- Expanded view - Performance and AMD FirePro.
Check the box Enable AMD CrossFireX .
If necessary, click and drag the slider to unlock support for displays connected to auxiliary GPUs. Not all AMD CrossFireX configurations support unlocking displays connected to auxiliary GPUs.
Click the Apply button.

Enabling AMD CrossFireX™

Enable AMD CrossFireX support to accelerate the quality and performance of 3D applications and games displayed on displays connected to the main GPU. When AMD CrossFire™ support is enabled, the best possible combination of GPUs to use is selected based on the current hardware configuration.

Note: If AMD CrossFireX support is enabled, Control Center automatically restarts. AMD CrossFireX is designed for applications running in full screen mode.

AMD Radeon™ dual-GPU graphics cards are powered by AMD CrossFireX technology. As a result, AMD CrossFireX support is always enabled for these boards.

- Standard view - Performance And Games > Gaming performance.
- Expanded view - Performance and Games.
- Standard view - Performance And AMD FirePro > Graphics Performance.
- Expanded view - Performance and AMD FirePro.
If necessary, use the desktop selection menu at the top of the page to select the desktop associated with the GPU to use as your primary desktop.
Check the box Enable AMD CrossFireX.As of Windows® 8.1, AMD CrossFireX support is enabled by default only for applications and games with a standard AMD profile or a custom application profile. To enable AMD CrossFireX for all games and applications - even those that do not have an application profile - select Enable AMD CrossFireX for applications without a profile.
If necessary, click and drag the slider to unlock support for displays connected to auxiliary GPUs. Not all AMD CrossFireX configurations support unlocking displays connected to auxiliary GPUs. Note: For optimal performance when running 3D applications, connect all displays to the main GPU and (if necessary) unlock displays connected to the secondary GPU.
Click the Apply button.

AMD CrossFireX is enabled and AMD CrossFireX automatically uses the best combination of GPUs for your system. Only displays connected to the primary GPU are available for use (additional displays must be running in extended desktop mode). Displays that are not included in the AMD CrossFireX configuration are also available for use. Displays connected to auxiliary GPUs remain usable only if support is unlocked.

If other GPU combinations are available, you may choose to use a different combination.

Note: If there are problems with your current AMD CrossFireX configuration, diagnostic information will be displayed at the bottom of the page.

Selecting GPU Combinations for AMD CrossFireX™

If your system has more than two graphics processing units (GPUs) that support AMD CrossFireX, you can select a specific combination of GPUs to use.

Note: When you change the GPU combination that is used for AMD CrossFireX, the Control Center application automatically restarts.

Go to the AMD CrossFireX page located in the groups below.
- Standard view - Performance And Games > Gaming performance.
- Expanded view - Performance and Games.
If you are using an AMD FirePro™ graphics card, you can navigate to the page using the groups below.
- Standard view - Performance And AMD FirePro > Graphics Performance.
- Expanded view - Performance and AMD FirePro.
From the GPU combinations drop-down list, select the combination to use. Each list option lists the number of GPUs that support AMD CrossFireX and the adapter index of the primary GPU, followed by one or more secondary GPUs.
Note: If there are problems with the selected combination, diagnostic information will be displayed at the bottom of the page.
Click the Apply button.

The selected GPU combination is used for AMD CrossFireX.

Show or hide the AMD CrossFireX™ logo

When AMD CrossFireX support is enabled, you can choose to display the AMD CrossFireX logo for 3D applications and games running in full screen mode. This logo appears in the upper right corner of the screen and indicates that AMD CrossFireX support is enabled. When AMD CrossFireX support is disabled, the logo is not displayed.

Additionally, for AMD FirePro™ boards, the logo is also displayed for applications running in windowed mode.

Click the Control Center logo on the Windows® taskbar (notification area) right click mice.
From the menu that appears, select the graphics card associated with the primary GPU for the AMD CrossFireX configuration, specify AMD CrossFireX Options and select Show CrossFireX status icon (if applicable) to display the AMD CrossFireX logo when AMD CrossFireX support is enabled. To always hide the logo even when AMD CrossFireX support is enabled, clear the check box.

Unlocking displays on secondary GPUs for AMD CrossFireX™

If your system supports displays directly connected to the secondary GPU in AMD CrossFireX, you can unlock support for the number of displays you plan to use.

Note: When you change the number of displays supported by the secondary GPU in the AMD CrossFireX group, the Control Center application automatically restarts.

Go to the AMD CrossFireX page, located in the groups below:
- Standard view - Performance And Games > Gaming performance.
- Expanded view - Performance and Games.
If you are using an AMD FirePro™ graphics card, you can access the page using the groups below:
- Standard view - Performance And AMD FirePro > Graphics Performance.
- Expanded view - Performance and AMD FirePro.
Make sure AMD CrossFireX is enabled.
Click and drag the slider to unlock support for displays connected to auxiliary GPUs.
Note: For optimal performance when running 3D applications, connect all displays to the primary GPU and (if necessary) unlock displays connected to the secondary GPU.
Click the Apply button.

AMD CrossFire™ Troubleshooting Tips

Below are solutions for common AMD CrossFire issues. For more information, visit the AMD CrossFire web page at www.amd.com.

Change Motherboard BIOS Settings Some motherboards may have a system BIOS setting that allows you to switch between single and dual PCIe® slot support. By default, one slot can be supported. For information on how to enable dual PCIe slot support, see the software manual. Using graphics cards with different amounts of memory Some AMD CrossFire configurations may use graphics cards with different amounts of memory; at the same time, after enabling AMD CrossFire requires a computer restart. This will force AMD CrossFire to reduce the memory on the graphics card with more memory to match the memory on the graphics card with less memory.

When you click the Disable AMD CrossFire button, you will be prompted to restart your computer to restore the original amount of graphics memory, or continue with the reduced amount of memory. Swap Cards Recommended If the primary graphics card is not inserted into the primary PCIe slot, a message may appear advising you to swap graphics cards. Although AMD CrossFire may be enabled in this case, rearranging the graphics cards in your computer may improve system performance.

To find out which PCIe slot is the primary slot, see your motherboard documentation. 3D client is active AMD CrossFire cannot be enabled while a 3D application or game is running, or a video such as a DVD movie is playing.

Close all open 3D applications, games, and movie applications, and then enable AMD CrossFire. AMD CrossFire is currently unavailable This error occurred because the AMD CrossFire system did not correctly detect the graphics hardware or there was a software issue.

Check that the graphics cards are installed correctly.
Check that the connection cable is connected correctly.
Close any running 3D applications.
Reinstall the Control Center software and drivers.

Screen rotation feature is not available or does not work Screen rotation feature is not available on AMD CrossFire systems. Video on screens flickers during system bootup This is normal during AMD CrossFire bootup. AMD CrossFire Starts in Software Mode This is normal on first startup after installing two AMD CrossFire graphics cards if neither card is installed in the primary PCI Express® slot. AMD CrossFire mode can be changed in the Control Center app. AMD CrossFire is disabled after reinstalling or moving cards If you change the AMD CrossFire configuration by reinstalling graphics cards in different slots on the motherboard, first disable AMD CrossFire and restore the factory default settings in the Control Center app. After rearranging the boards, enable AMD CrossFire. This will allow the computer to detect new configuration.

Found a typo? Select the text and press Ctrl + Enter

Very often I hear questions from inexperienced PC users: “What are Sli and Crossfire?” "What is the performance gain from two video cards?" and "Is it worth buying another video card to run Sli or Crossfire mode?"

Today we’ll look at all these questions piece by piece, and I’ll talk about the pros and cons of buying an additional video card for Sli or Crossfire mode.

Let's start with the most basic concepts, for those who previously had no idea what this technology was. In fact, a computer can work with two or more video cards. It all depends on the number of PCi-Express slots for video cards on your motherboard. If you connect two video cards from Nvidia, then such a combination will be called Nvidia SLI. If you connect two video cards from AMD, then such a combination will be called AMD CrossfireX. And now I will tell you in detail about the features of each bundle. Its pros and cons and whether it is worth the money spent that manufacturers ask for their video cards.

Two video cards in one computer sounds nice and cool. In theory, they should give us twice as many frames per second in games. Increase performance twice as much as a single graphics card. In practice, everything is a little sadder than our assumptions. Let's look at everything in order.

Let's start with the Nvidia SLI bundle. Video cards from "green" are more expensive than competitors represented by AMD and SLI technology in price category Price dependence was not spared either. For Nvidia, a combination of two video cards will be more expensive, since the combination requires a motherboard with SLI support “specific” for such purposes. It's all about "licensing". Nvidia does not allow SLI connections to be installed on all motherboards. For such purposes, there is a separate group of motherboards with the “SLI Ready” icon on the box and directly on the motherboard itself.

Manufacturers of “special” motherboards pay “green” for the opportunity to run SLI connections on their products, but we, ordinary users, overpay a little for this opportunity. In the box with such a motherboard there should be a special SLI bridge that allows you to connect these video cards; you can connect video cards “software”, that is, without an SLI bridge.

But in this case, you should not expect a high performance increase. It is also worth paying attention to the fact that you need to connect only identical models of Nvidia video cards. For example, two gtx 980, or two gtx 970. That is, it is not recommended to install two different video cards, since the performance will be multiplied by the worst of the video cards. That is, if you install a gtx 550 and a gtx 980, then you will have the performance of two gtx 550. The manufacturer of the video cards does not matter. That is, if you have two gtx 980, but one is from MSI and the other from EVGA, then the performance increase will be calculated according to the one with the lowest frequencies.

Let's move on to the Crossfire combo. It's much easier here than SLI. You can connect two video cards on any motherboard that has two or more PCI-Express slots. That is, so that there are connectors where they can be inserted. It follows from this that you will not need a bridge to connect video cards, but if you connect video cards without a bridge, you will lose about 10-15% in performance. You also don't need the same video cards. But this does not mean that you can connect absolutely any video cards. You need to connect video cards from the same series, not necessarily the same model.

It's also worth noting that memory sizes do not add up. That is, if you connect two video cards with four gigabytes of video memory, then four gigabytes of memory will be available to you. Also, if you connect a video card with 6 or 8 gigabytes of memory with a video card that has only 2 gigabytes, you will have access to two gigabytes of memory, the rest of the memory will simply be idle and “not work”.

We should also not forget that not all games have support for SLI or Crossfire, and often, instead of the twofold increase in performance “promised in theory,” we get, at best, an increase of 60-70%, and sometimes there will be no increase at all, since the game it was simply not provided for combinations of two or more video cards. It very rarely happens that the performance increase reaches 90-100%, but this happens very rarely.

Also, do not forget that two video cards, although they do not bring twice the performance increase, their power consumption is doubled. Therefore, when deciding to buy an additional video card, you should think about upgrading the power supply. To support two video cards, a power supply of 750 watts or higher is required. Also, a combination of video cards requires a fairly powerful processor. Intel Core i5 or i7 will be enough.

Now let's move on to the feasibility of connecting two or more video cards. Based on the above, there is no point in connecting budget or mid-class video cards, since for the money of these two video cards it is better to buy one more powerful one, with which no problems should arise. More suitable option for combining two or more video cards there will be video cards from Nvidia: gtx970, gtx 980, gtx 980ti, Nvidia cards of the Titan series (Titan Black, Titan X, Titan Z), and cards from AMD: R9 290, R9 290X, R9 390, 390X. Such bundles will be useful for players who want to play in 4K resolution with high FPS, or for players who play in FullHD or 2K resolution, but want their system to produce 80 FPS and above.

With this I consider my manual complete. If you have any questions, please contact us in the comments - we will try to help you.

Avid gamers have probably come across or at least heard about technologies called SLI and Crossfire, which are usually referred to as the graphics system of a computer or laptop. In most cases, such terms apply more to stationary systems (this will be discussed a little later). However, sometimes for normal computer operation you will need to know how to disable Crossfire or SLI when such modes are not used. This is what we will talk about now.

SLI and Crossfire: general concepts

It’s probably worth starting with the fact that, from the point of view of modern computer technology, SLI and Crossfire are specialized modes that support the installation of two or more video cards on a computer.

In stationary systems, two independent video adapters are simply inserted into special slots located on the motherboard. Sometimes you can come across a situation where the motherboard already has an integrated graphics chipset, so to speak, “sewn” into the board, and another one is installed in parallel with it.

Now we will dwell on both modes in a little more detail, and at the same time we will look at how to disable Crossfire (SLI) using several simple methods if necessary, especially since both modes are practically the same in operating technology.

What is SLI?

SLI technology, which involves installing multiple graphics adapters into the system, was developed by nVidia and implies the use of cards only from this manufacturer.

In principle, this mode can be called a kind of conditional electronic adapter that connects two video adapters, allowing them to combine their capabilities into one.

What is Crossfire?

Crossfire is a complete analogy of SLI technology, but the authorship of this development belongs to the no less famous AMD corporation.

An interesting fact is that, as practice shows, combining two or more AMD video cards in Crossfire is much cheaper than using an SLI bridge when installing nVidia cards. In addition, nVidia technology does not allow installing such bundles on all motherboards in a row. But if we consider the question of how to disable SLI-Crossfire Dual Graphics, the solution in both cases will be the same. But first, let's look at some features of their use.

Features of connecting video cards in SLI and Crossfire modes

Firstly, every user of a computer system must clearly understand that connecting two or more graphics adapters to the motherboard is possible only in cases where the motherboard itself supports this feature.

For example, to use the SLI mode, the board must have the appropriate markings, otherwise, no matter how much you try to install two cards on it, they will not work together. The same applies to the simultaneous use of a discrete and integrated adapter. Here you will have to be content with only one of them.

Secondly, you should pay attention to the fact that to work in conjunction with SLI technology, you can install only video cards based on the same chips (for example, nVidia GTX 970 and 980 series, Titan series chipsets or two identical GT cards, etc. .). Please note: a combination of 9600 GT and 9800 GT will not work.

It's a different matter when Radeon cards are used. Here you can use “multi-chip” configurations, for example, Radeon 2600 and 1950. Very often, R9 series cards are used to increase graphics system performance. Indeed, such pairs allow you to use maximum capabilities for games with Full HD or 2k resolution. Some users use such combinations to increase the overall frequency of the storyboard, say, to achieve more than 80 fps (frames per second).

Thirdly, do not forget that for SLI cards a special adapter must be used, which must be supplied either with the card or with the motherboard. Without it, the two cards will again not work together.

Myths about using Dual Graphics mode to increase graphics performance

Some naive users install two cards to increase performance, believing that it will double (two cards on board). It's a delusion. The increase in productivity, as practice shows, rarely exceeds 20-30%.

In addition, this indicator is calculated based on a weaker card. For example, if we have 8 GB of memory on one card and 2 GB on the other, whatever one may say, the user will receive only 2 GB at the output. The same applies to installing two cards, say, with 4 GB of memory each. The output will remain the same 4 GB.

One more point: if one MSI card, and the second is EVGA, the calculation of the total performance will be made precisely according to the one that has the lowest frequencies. So, as we see, there’s no point in flattering yourself.

How to disable SLI/Crossfire using the simplest method?

Now let's move on directly to the process of disabling these modes. Probably every user understands that the question “how to disable Crossfire or SLI mode” comes down to not using a second graphics adapter in the system. And, as is already clear, the simplest solution is to simply remove one of the cards from the slot on the motherboard, which applies to desktop computers.

But modern ultrabooks can also install additional equipment, in particular the same video adapters that, in principle, can use the Crossfire mode. How to disable one of the cards on a laptop? As easy as pie. The methods described below are suitable for both desktop computer terminals and laptops.

How to disable SLI (Crossfire) mode for a discrete adapter via BIOS?

To disable both modes, you can use the BIOS settings. Login is done by pressing the Del, F2, F12, etc. keys (it all depends on the BIOS version and developer).

Here we are interested in the tab containing the configuration called Onboard, Integrated Devices, etc. We enter the parameters and set the mode to Disabled (sometimes Off). That's all.

You can go to the Advanced section, where the settings of the mode itself will be indicated if you are using discrete rather than integrated adapters.

Using Device Manager

Now let's see how to disable Crossfire AMD or SLI nVidia using standard Windows tools. To do this, you need to go to the standard “Device Manager”. This is done either through the “Control Panel”, or through “Administration”, or using the devmgmt.msc command.

Here you need to go to the video adapters section, where the installed devices will be indicated. In this case, as in all other situations, the question of how to disable SLI-Crossfire comes down to making one of the cards inaccessible. Select the card to disable and right-click to open the properties menu, where there is a button to disable the device. You can use a similar command directly from context menu. After this, you won’t even have to reboot the system.

Disabling modes using “native” utilities

Despite the simplicity of the described methods, it is best (and safer) to use “native” utilities for setting up and managing graphics adapters, which are installed automatically when installing the appropriate drivers, or installed additionally.

For nVidia cards, you can use GeForce SLI Profile Tool, PhysX, Riva Tuner, etc. For AMD chipsets, utilities like ATI Tray Tool or ATI Catalyst Control Center and others will be useful. Their use is simpler, so much so that you don’t even have to go through the system configuration or BIOS to change this or that parameter. If you look into it, this solution to the problem we are considering (how to disable Crossfire/SLI) will be more effective, and it will even eliminate the occurrence of conflicts between installed equipment (unfortunately, this also happens).

Instead of an afterword: should I disable dual graphics mode?

It remains to add a few words about the advisability of using such modes. Actually, the answer to the question: “How to disable Crossfire (SLI)?”, I think, is already clear. As for installing two or more video cards in one system and using them simultaneously, there are quite a lot of conflicting opinions. The fact is that you may not get much of a performance boost, and hardware conflicts are not excluded.

Of course, if the system does not use graphic capabilities to the maximum, you need to disable these modes, because the simultaneous operation of two cards can lead to severe overheating of the computer, double power consumption by the graphics system (after all, two cards are installed), as well as to the inoperability of some games, the program code of which simply does not support such modes or is not fully least adapted to their use.

In addition, it is not recommended to include bundles in the form of budget cards or mid-range adapters. It’s better to buy one more powerful one instead of two of these. Productivity will be much higher and there will be fewer problems. And in terms of money, this option is often preferable.

However, if you look at it, it is sometimes possible to use such modes, but in situations where two cards are not used, it is recommended to disable one of them, and you need to use a special one for this. software, designed to manage all parameters of graphics adapters. And such a shutdown is carried out, as they say, in one click.

crossfire ) - a technology that allows you to simultaneously use the power of two or more (up to four graphics processors at the same time) Radeon video cards to build a three-dimensional image.

The technology was announced at the Computex international exhibition in Taiwan.

It is worth noting that combinations of some video cards can be much more efficient, productive and financially profitable than one more powerful and, accordingly, much more expensive card. But, as in the case of NVIDIA SLI, there will be a performance increase from using two video cards in the system only in applications that can use 2 or more GPUs. In older games that cannot work with Multi-GPU systems, the overall performance of the graphics component will remain the same, in some cases it may even decrease; so for fans of old, but demanding games, the best decision would be to buy one very powerful video card rather than buy a second one of the same type and then combine it into a CrossFireX system. It is also worth noting a significant drawback of CrossFire: this technology does not work when running the application in windowed mode.

Construction principles

To build a CrossFireX system on a computer, you must have:

a motherboard with two or more PCI Express x16 slots (for versions R9-285, R9-290 or R9-290X also with an AMD or Intel chipset of a certain model that supports CrossFireX);
powerful power supply, usually with a power of 700W;
video cards with CrossFireX support;
A special flexible CrossFireX bridge for connecting video cards.

Video cards must be of the same series (with some exceptions), but not necessarily the same model. At the same time, the speed and frequency of the CrossFire system are determined by the characteristics of the chip of the least productive video card.

A CrossFireX system can be organized in the following ways:

Imaging algorithms

SuperTiling

Scissor

The image is divided into several parts, the number of which corresponds to the number of video cards in the bundle. Each part of the image is processed completely by one video card, including geometric and pixel components.

SuperAA

This algorithm is aimed at improving image quality. The same image is generated on all video cards with different templates smoothing. The video card smoothes the frame with a certain step relative to the image of another video card. The resulting images are then mixed and output. This ensures maximum image clarity and detail. The following anti-aliasing modes are available: 8x, 10x, 12x and 14x.

The driver takes one frame from the APU for every two frames from the discrete card).

Despite all the seductiveness of such an asymmetric CrossFire implementation, there are serious drawbacks:
Firstly, this only works in applications using DirectX 10 or. And if DirectX 9 or an earlier game engine is used, then performance degrades to the slower of the two installed graphics cards (however, according to AMD's latest statements, when using DirectX versions below 10, programs must access the faster of the two installed graphics cards).
Secondly, for Dual Graphics to work, the graphics performance ratio must be at least two to one; if the video card is three times faster than the Llano GPU, then Dual Graphics will not work.

In OpenGL, Dual Graphics is not supported and it always runs on the GPU that controls the main output of the display.

When choosing a video card from AMD, the user may notice the CrossFire parameter in the list of options. This is a special technology that was developed by AMD engineers with the goal of combining several video cards into one system. Thanks to the use of CrossFire technology, it is possible to extend the life of old video cards, as well as increase the maximum power of the system several times. But CrossFire technology has a lot of nuances that must be observed for it to work correctly and for video cards to deliver the maximum of their capabilities. In this article, let's look at the subtleties when setting up CrossFire and combining several video cards.

Table of contents:

What is required to connect two video cards via CrossFire

To combine two video cards into one, you will need not only their presence and two slots on the motherboard. There are a number of conditions that must be met to take advantage of CrossFire technology and unlock the potential of two GPUs. Before combining the two AMD cards via CrossFire into one common performance element, ensure that the following components meet the necessary requirements.

. The motherboard must have at least two PCI-Express. It is important that the slots have maximum throughput. For modern motherboards this is x16. For now, pay close attention. Only if you have x16 bandwidth for both video cards connected to the motherboard will you be able to achieve maximum performance. Often, motherboards have one main x16 connector and several auxiliary connectors with lower bandwidth. It could be x8 or x4. Some video cards do not have a PCI-Express slot with x16 bandwidth at all, and all slots are x8.

Please note: To connect AMD video cards via CrossFire, you can also use connectors with x8 bandwidth or one x16 and the other x8. But this will reduce the overall performance of the combined array.

The throughput of the connectors is marked with a corresponding inscription next to them. If it is x16, it will be written PCIEX16_1, PCIEX16_2 and so on. If x8, then PCIEX8_1.

In addition to having two connectors on the motherboard for connecting video cards via CrossFire, it must support this functionality at the chip level. It is important to note here that not all chips support CrossFire, and it is better to check the fact of compatibility on the website of the motherboard manufacturer. It is also worth noting that only motherboards based on AMD and Intel chips work with CrossFire technology. If the motherboard is made on an Nvidia chip (a company that is a direct competitor to AMD), it definitely does not support the patented CrossFire technology. Please note: Motherboards that support CrossFire have this marking on the box.

. Ideally, it is better to combine two identical video cards - of the same series and from the same manufacturer - into an array via CrossFire. But this is not always possible, so on the AMD website, as well as on the websites of video card manufacturers, you can find detailed tables with the compatibility of certain graphics processors with each other. Important: If the cards are CrossFire compatible, but one of them is more powerful than the other, you should know that the more powerful model will not be able to fully operate. The cards will work at the level of two weak cards from this pair.

It is worth noting that video cards with CrossFire support always come with a bridge to connect them. It is a small wire with a corresponding logo and a connector on both sides.

Power unit. The video card is one of the main consumers. When there are two of them, and they work simultaneously, especially with the same x16 bandwidth, this is a very serious load on the power supply. You need to have the right power, and also take into account whether it has the required number of connectors to connect all the components.

Housing and cooling system. Another point that is often forgotten when wanting to build a computer assembly with two video cards connected via CrossFire is the presence of a good case. Video cards must not only fit into the unit along with other components, but it must also have a good ventilation system. It is wrong to think that the coolers on the video card itself are enough to cool the chip. The case must be kept low temperature, and when running two video cards it will be significantly higher than when running one. Therefore, the case must be equipped with its own high-quality coolers to remove hot air.

Hello friends, today I will tell you about AMD CrossFire. This technology allows you to simultaneously use several video cards on your computer to improve video quality. This topic is quite specific, and first of all it will be of interest to demanding gamers, PC hardware specialists and, of course, all enthusiasts who want to understand modern computer technologies.

Now, perhaps, you won’t surprise anyone with multi-core devices. And if CPUs installed on the motherboard required more advanced manufacturing technologies to implement this idea, then it was obvious: just install several video cards together and synchronize their operation.

This required a certain software algorithm that processed video and combined the efforts of individual cards and a device for exchanging information and transmitting a video stream between them. This is how the technology on the basis of which CrossFireX was created appeared.

How is the video processed?

For general development, I will describe how it works. The picture was split into individual elements or frames processed by separate modules. They also smoothed the image in different ways. All this, with the subsequent merging of streams, made it possible to obtain higher quality and more detailed video with high frequency frames (fps).

To implement CrossFireX “at home,” AMD has somewhat simplified the task for supporters of this brand.

In collaboration, you can use up to four video cards from different manufacturers, of any model. The main thing is that they are based on one AMD chip (they are of the same generation) and, of course, support AMD CrossFire technology.

Also, in addition to the ability to work with a specific motherboard, video cards must be compatible with each other.

You can check this here (for some video cards):

Or google it on the Internet if you didn’t find your device in this table. By the way, here is the official AMD website, where you can select your card from the list and find out which ones are compatible with it for Crossfire: https://www.amd.com/en/support

Perhaps this information will somewhat upset those who once bought any video cards for gaming, and now decided to join their efforts for gaming.

It is worth considering that with different card parameters (memory, frequency), the system will be guided by the weakest of them.

Install and connect hardware

Connecting system components is not particularly difficult, but requires certain conditions to be met:

The cards are simply installed in PCI E slots with x16 bandwidth. If there is only one, then the only option left is to also use PCI Ex8. Using weaker connectors will not give the effect of AMD CrossFire, so if this condition is not met, there is no need to rush into buying a second video card.
Next, we connect the video cards to the power supply and get ready to count the watts of their total power consumption. If the power supply has an appropriate reserve, then we simply connect the power supply to installed modules. If not, we look for and install a new power supply with the required power reserve.
Since 2007, a special bridge has been used for the interaction of video cards, which allows up to 4 video cards to be connected in series. It simply plugged into the appropriate connectors. In addition, it is possible to use PCI E directly for this purpose, but due to its increased load, there was a loss of efficiency of this system. Today, the XDMA protocol, a more advanced type of bridgeless connection, is used for joint processing of video streams. In general, it all depends on the year of manufacture of the video card. If it’s new (especially after 2016), don’t worry at all. If older, the kit should include a bridge. Install it here.

Software

The iron has been delivered. Go. Just download the updated drivers for your video cards first, because next we will need to activate AMD CrossFireX in the computer settings. There's nothing complicated here. Either the system itself will recognize its new features and offer to enable them, or we launch AMD Catalyst Control Center, find “Performance” in the extended menu and mark the choice with a dot: “Enable AMD CrossFireX” mode.

And then the moment came when this system it's time to try it. To do this, you will need modern games, with highly detailed elements, running in 4K format and, of course, with CrossFire support under the cooperation program with AMD.

Yes, yes, not all games support this technology! Check the support for each game you want to run in this mode.

Once you launch it, you can fully enjoy this technology. Also, the joint operation of video cards is excellent when using multiple monitors simultaneously.

Well, perhaps that's all.

Reflections on expediency

Is the card game worth it? You decide. The opportunity to increase fps performance is, of course, highly valued, but do not forget about the rather high cost of the video cards themselves + a new power supply.

I'll be honest. In most cases, instead of two video cards, it is more profitable to buy one more powerful one. But in a situation where another is purchased in conjunction with an existing one, there is a reason.

There is another option when AMD CrossFireX remains the only way to improve the capabilities of your PC: this is when it has the most powerful (available on the market) AMD video card installed. Only by installing one more of these can you get fantastic results. The costs for this will, alas, be appropriate.

And yes. If you are a cool miner, then of course a bunch of several cards will bear fruit.

I feel, dear readers, that you are thoughtful. And this is good, because there are different thoughts: some talk about the feasibility of this idea, while others began to study the specification of hardware in a PC and look for options on how, where, from whom they can buy the necessary video card cheaper.

Good luck to you and see you again on the pages of my blog.

In the article we looked at the technology of combining several video cards for their joint work from Nvidia - SLI (I advise you to familiarize yourself with it, because I will refer to it), now we will look at a similar technology from their competitors - AMD CrossFireX.

History of ATI CrossFire

In the late 90s, ATI was not doing very well - in 1999, Nvidia introduced two new generations in one year - Riva TNT2 and GeForce 256. 3dfx, the second competitor, in 1998 introduced SLI technology, which allows you to combine two Voodoo2 video cards together on one PC . But ATI was only able to present RAGE 128 (and a little later overclocked PRO version), in which there was nothing innovative. Realizing that it would not be long before they left the video card market, they decided to copy the SLI technology from 3dfx and released a “dual-headed” ATI RAGE FURY MAXX video card, which included two RAGE 128 PRO GPUs. The technology itself for combining video chips was called MAXX (Multiple ASIC Technology), and was purely software: each of the GPUs completely prepares one frame, and when displayed on the screen, they alternate. In fact, it was the spitting image of AFR (Alternate Frame Rendering) technology, which is still used today.

But, however, the FURY MAXX video card simply had two GPUs; it was impossible to combine two video cards from ATI - in those days there was an AGP bus, and there was only one this port on motherboards. In 2004, the PCI Express bus was introduced, which made it possible to divide the lines - and therefore make several ports and connect several video cards. Nvidia took advantage of this by introducing the new SLI technology, and ATI, which changed the name MAXX to CrossFire.

There were enough differences between them then: to create CrossFire, you needed a so-called master card - it had an overlay chip inside, allowing you to receive data from the slave card and combine it pixel-by-pixel with the main card. The connection took place through a special DVI-DMS cable, and the monitor was connected through another DVI connector extending from the master card:

This was terribly inconvenient, and in the future ATI came to the same point as Nvidia immediately - data is transmitted through a special bridge, and there is no such thing as master or slave anymore (and even further, AMD, which bought ATI, abandoned bridges altogether) . And if this first difference was a minus for ATI, then the second, on the contrary, is a plus: if in SLI you can combine video cards of only one series, then in the case of ATI, video cards can even be of different generations.

Subsequently, in 2008, AMD introduced Quad CrossFireX, a technology that allows up to four video cards to be combined together, and now the technology for combining video cards is called AMD CrossFireX (or CF for short).

Imaging algorithms using CF

The first algorithm is not new - it is also successfully used by Nvidia. It's called Slicing(Slicing), and consists in the fact that the frame is divided into two parts - one is processed by one video card, the other by another:

Moreover, the parts may not necessarily be the same: it all depends on the complexity of the scene, and the rendering areas for each video card may be different. This algorithm is poorly suited for games, because it is impossible to calculate the complexity of a frame in advance.

ATI/AMD came up with the second algorithm themselves. It is called (from the English tile - tile). The essence of the algorithm is that the entire frame is divided into “tiles” of 32x32 pixels each, and each video card prepares its half of the tiles in a checkerboard pattern:

The advantage of this method is that each of the two video cards will account for on average half the load, that is, there is no such thing as in Slicing, when one video card got the sky in the game and it prepared the frame in 5 ms, and the other got a bunch of textures of the ground, buildings, and so on further, and she prepared the frame in 20 ms: here each of the video cards got the sky, and the textures of the earth and other objects. But, as one would expect, there are also disadvantages: firstly, the most exact matching of the characteristics of the video cards is required: if in Slicing the frame can be divided proportionally to the performance of each GPU, then in Tiling the load is divided exactly in half, so the video cards must be completely identical. Secondly, the geometric load is not divided between the cards, but in games it is usually low and there are no problems with this.

The third algorithm AFR, common with Nvidia - each of the video cards prepares frames one by one:

The advantages are the same - no artifacts when rendering a frame, you can easily parallelize the load across 4 GPUs. Minus - all frames have different complexity, which can lead to jerky pictures at low fps.

And the last algorithm of “honest” CrossFire is SuperAA(super smoothing). The principle is similar to that of SLI AA - each video card smoothes the image with a certain step relative to the other, and then the resulting images are stitched together into one frame. However, there are still differences from SLI AA - in the case of Nvidia, MSAA anti-aliasing is used, in the case of AMD - SSAA (it gives a slightly better picture, but also requires more resources). Anti-aliasing modes from x8 to x14 are available (let me remind you that Nvidia has a maximum of x32).

In the case of laptops on AMD APUs, which include both a processor and integrated graphics, AMD was more cunning than Nvidia: if the laptop has discrete graphics from AMD, then it can be combined with integrated graphics Dual Graphics when both video cards are working (let me remind you that Nvidia has Optimus technology, which allows you to use either discrete graphics or integrated graphics, but not both). However, this method has its limitations: firstly, it only works with DirectX 10 and higher (in principle, taking into account the fact that games with DirectX 9 are old and undemanding by modern standards - CF is not needed there). Secondly, the difference in the performance of discrete and integrated video cards cannot be more than twofold, that is, combining the graphics integrated into the APU with some R9 M390, alas, will not work (again, here the integrated graphics are like the fifth wheel in a cart and will only get in the way, so AMD basically did the right thing).

System requirements for CrossFireX

Almost everything here is the same as for SLI from Nvidia (so I won’t rewrite the requirements a second time), but there is one important difference - there is no need for bridges to connect video cards at all (it’s funny - in the thousandth line, Nvidia not only did not abandon bridges for SLI - she introduced new, even faster ones), the CF controller is now located on the video card board itself, and data is transmitted via PCI-E. There are no other significant differences - video cards of the same series are still connected, the memory capacity is still limited to that of the weakest video card in DX 11 and is summed up in DX 12.

And the most main question- does it make sense to do CF? Yes, it has. Everything is simple here - green fans can buy one GTX 1080 Ti, which will be enough for all modern games, so SLI is basically not needed for games. AMD has the most powerful graphics so far - the RX 580, which is generally at the level of the updated GTX 1060, and which is only enough for FHD (in 2K you will have to significantly reduce the settings, or play at 30-40 fps). So here CF makes sense - two RX 580 will allow you to play normally in 2K on ultra graphics settings.

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