So, to build SLI, you need two identical cards, they can be from different vendors. For example, GTX 780 from Asus and GTX 780 from Zotac. You need to know the following two points: the first, video memory is not added (promise to fix in DX 12). And the second - if the cards have different frequencies, then they will work at a lower frequency. That is, one 850 MHz card on the chip, the other - 900 MHz, then the tandem will work at 850 MHz. You can, of course, raise the frequency of the first to 900. In general, the essence is clear. In AMD / ATI everything is the same, but they can combine two video cards within the same family. That is R9 390 + R9 390X or 7850 + 7870 and so on. On the other hand, some of the cards on the card are muted more reliably to equalize. This means that R9 390 + R9 390X will be equivalent to two R9 390. Therefore, it makes no sense to fence such a bundle, part of the card will be idle.
To build a multi-card platform, the motherboard must have CrossFireX and / or SLI support. Most boards in the middle price range support CrossFireX. But for SLI have to pay extra and take the motherboard "cooler."
Scalability. Consider the example of the GTX 960.
If we compare the characteristics of 960 with 970 and 980, we will see that the half of the 980 chip is 960. We sawed GM204 in half and got GM206, roughly speaking. Theoretically, SLI 960 should be equal to GTX 980. But this is all theory. In practice, the increment from the second graphic accelerator is 70-80%. In rare cases, 90%. As you can see, even without tests 980 will be ahead. Therefore, the SLI 960 is comparable to the 970. At factory frequencies, 970 is still inferior to two 960. But it's worth overclocking 970, and it immediately goes level or bypasses the 960's. And now the question arises: is it worth it? Counting prices, the new 970 - 400 $, 960 4 GB - 230 $. The 4 GB version is mandatory, otherwise we will rest on the memory ceiling. 400 $ vs 460 $. To this amount, you need to add the cost of the motherboard with support for SLI.
With a bunch of two cards, the hull plays a very important role (!). 960 themselves are very cold and energy-efficient, it seems that you can not sweat at all. But this is only at first glance so. Let us dwell on this in more detail. Video cards are divided into reference and non-reference.
In general, the non-reference design of the board and CO is used. They are all better than all the reference, except one ... The air remains in the hull, while the turbine-type SB blows the most out of the hull. Therefore, when using two notref cards begin to warm each other. But there are exceptions, for example, here is such a map.
Go ahead, the great importance is the location of PCI-E slots on the mat. board. Video cards, as a rule, occupy two expansion slots. Hence, the distance between slots should be such that when installing two graphics adapters between them there was a distance. Example, the "correct" board is lower in the pictures.
The most competent SLI. Maps of the turbine type and the distance between them.
But you do not need to do this. The top map has nowhere to take the air. Therefore, the turbine is untwisted as much as possible, in order to draw in at least part of the flow through the slit.
What to do with 3 or 4 cards, you ask. From the third card, the increase is 40-60%. To organize 4 cards mat. you still need to find a fee. All sorts of Rampage Extreme are designed for this. The processor needs an appropriate one. Such systems are used for benchmarks. I think, who needs a permanent such, there is money for the organization of the NWO. Plus, do not forget about the BP. Two average cards will still consume more energy than one top (or pretoptop) one.
As you can see, there are enough nuances for organizing a multi-GPU. It is worth considering the fact that not all games are well optimized for several cards, sometimes you have to wait for the driver. But it is worth acknowledging that in recent years there has been noticeable progress. On example 960 it was possible to see that such a bundle is not expedient. GeForce GTX 970 I would not connect either, because there is a 980 Ti. Bonus of 6 GB of memory. A powerful one-chip is better than a couple of medium-sized ones. (from)
In my opinion, it's only necessary to build a tandem of cards from tops. For example, SLI GTX 980 Ti for 4K. For this solution, this is a necessity.
How to be the one who has an old card, for example, GTX 660/670 or Radeon 7870? Now you can buy a second for $ 125. Is it worth it? Precisely not, due to 2 GB of memory, 660/7870 is hotter than the new 960. I know a person who had a CrossFireX of 7850 hardly cooled. But to sell for this money card, to report $ 200 and buy something new will be more rational. With a single chip will always be more reliable. Plus, optimizing for new maps faster and better.
The top AMD Fury X is ideally suited for CF, you can put it close, the SWO here is very handy. Excellent bunch for 4K. While 290/390 / X is not worth combining at all, very hot and hungry chips.
conclusions
Yet CF and SLI are a lot of enthusiasts. To unite there is a reason only top-end cards. In the future, take mate. fee with the support of these technologies and expect that in a year or two there will be a second card I would not. There will be new maps, it is easier to change the map and not bother about cooling and optimization of toys. Therefore, when building a system from scratch, you need to determine exactly whether you plan to put 2 cards at once or it's just an illusion of perspective.
I hope someone has benefited from this material. Everything written above is my personal opinion. Write how you feel about CF and SLI.
Thank you all for attention!
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Install the second video card in the gaming computer, perhaps, every gamer wants. This will not only substantially increase productivity graphics subsystem, but also get the opportunity connect more monitors / televisions. If configurations with multiple monitors are required relatively few, then increase the power of the computer for more realistic and smooth 3D graphics - the dream of any admirer of computer games. How to install two video cards in SLI or CrossFire mode You will learn from this article. Please kindly ...
Before you run to the store for a new graphics accelerator - you need to make sure that the motherboard of your PC has a free slot PCI-E for installing a second video card. Unfortunately, sometimes it happens that there is an additional slot, it is free, but ... nothing can be installed in it for a simple reason - it is blocked by the cooling system of another device. Glory to computer gods - this situation is quite rare, and if you have a modern full-sized ATX board, you can usually install even more than 2 video cards. By the way, when installing a second card with a GPU, the access of cold air to the cooling system of the first video card becomes much more complicated. We recommend to take care of their additional blowing and proper organization of air flows in the case of the system unit. It is quite an acceptable option to become, which allows you to assemble a gaming computer with a pair graphics cards in a small amount.
Note that when combining Radeons from AMD by technology (or GeForce from nVidia in mode SLI) it is recommended to choose the same video cards (built on a single chip / can be different manufacturers). Modern powerful models have a fairly large consumption of electricity - you should definitely have a powerful PB in the computer. can be very simple - it allows you to use it for other purposes. To get a significant increase in speed in games it is necessary to ask a question and (one more on this topic) - if there are 4 GPUs from the TOP segment, you can not get any acceleration if a weak CPU is installed in the system. Only a powerful processor can fully unlock the potential of modern graphics solutions in a gaming computer.
We will assume that with the above issues you have figured out, bought a video card (for example -) and are ready to start installing and configuring the system. Immediately in the process of "sticking" the card into the computer there is nothing difficult: disconnect system unit, remove from it a side cover, clean the computer of dust, open the plugs of the compartments for expansion cards on the back of the system, install a second graphics card in the free PCI-E slot, fix it with a screw, connect additional food (6/8 pin). If the video cards have connectors for connecting them to each other, then you need to do this with the "bridge" that comes with the kit. The monitor is preferably connected to the output of the card, which is located in the first (upper) PCI-E slot. After that, you can close the computer and boot into Windows to enable crossFire mode or SLI. We are talking about Windows - as the most common operating system for gaming computers. If there is a need (re-) to install Windows 8.1, then it will be very handy.
After the installing a second video card, it is recommended to download and install latest versions drivers for the graphics subsystem of the computer. This allows maximum use of the capabilities of two GPUs in the most modern games. You can download the driver on official AMD or nVidia websites. If you want, you can use the latest version of the driver-pack, for example - "DriverPackSolution" (DRP) or "SnappyDriverInstaller" (SDI). The second package is interesting in that if you have an Internet connection, the installer's shell itself can detect updated versions of drivers on the network and download them to your database.
The case remains for small - include combine video cards in SLI or CrossFire in the control panel graphics driver. For solutions based on the AMD GPU, this is done in the " Catalyst Control Center". Go to the "Gaming" - "AMD CrossFireX" section and enable the " Enable AMD CrossFireX". For nVidia cards, open " NVIDIA Control Panel", Go to the" 3D Settings "group and select" Configure SLI, Surround, PhisX ". In the right part of the window, in the "SLI configuration" group, Maximize 3D performance"(Below this will display the status" SLI enabled»).
Next, you can run a game or benchmark to make sure the computer is in 3D games. Do not be surprised if the FPS meter reading has not grown 2 times - not all games are well optimized to work with several video cards. In addition - the culprit of the lack of doubling the speed (+ 100%) may be the insufficiently fast CPU, as discussed at the beginning of the article. A typical increase in FPS is in the range 70…90% compared to the system where one graphics adapter is installed. And when you install two identical monitors at once - there is a twofold increase in the screen area ...
Opening a terrible secret, we say that modern technology allows you to combine more than 2 video cards in one PC, but it makes sense (there is a significant increase in fps) only for 3D games at ultra-high resolutions and choosing the maximum picture quality ... By the way, additional expansion cards may be needed not only to accelerate games, but for. And finally: get ready to increase the noise level from the cooling systems of powerful GPU - maybe you should think about switching to?
As it is already clear from the title of the article, I bought a second video card and decided to take the opportunity to write a detailed article on this topic. Let's start from the very beginning - what is Crossfire?
AMD CrossFireX (was originally called AMD CrossFire)- this is the technology of AMD, which allows you to combine several video cards in one system to improve the computer's performance in building 3D models and graphics. Of course, this technology is mainly intended for gamers, besides not the poorest, since video cards and motherboards supporting this function are at least in the middle price category. Although the price is not the only nuance that you need to know before buying, and now we will consider them.
What you need to buy in the system unit to support CrossfireX
So, first, I'll list what we need to buy in order to build a full-fledged CrossFireX:
1) Motherboard (you can buy in OGO.ru). Here, in principle, nothing is complicated, but before buying, you should carefully read the specification on the manufacturer's website, as important information is often hidden in stores. So, the first is technology support CrossFireX, but there is one nuance - on the motherboard there should be two full-fledged PCI-E x16 ports working in x16 + x16 mode, but at least x8 + x8 (the difference is a few percent, but still takes place), although ideally, it is better to use the first option. In stores, very often they do not disclose information that two of the three PCI-E x16 ports work in x4 mode and although they are possible for use, but, due to weak use of the second video card, they are not suitable for building CrossFireX. The purchase of a second video card in this case simply does not pay for itself. In the best case, they will write about this in the "Additional information" section, but as practice shows, there is not. Therefore, do not be lazy to go to the official website of the manufacturer and view the specification for the motherboard, which you are going to buy, as here the manufacturer is obliged to indicate this data. For example, here is the information on the Gigabyte website about my motherboard:
To make the search a little easier, there is already a list of chipsets on which there is technology support CrossFireX,but this is only an approximate list, the final support is specified in the specification on the manufacturer's website.
for mattplats AMD AM3 +:
AMD 990FX (x16 + x16, PCI-E 2.0)
AMD 990X (x8 + x8, PCI-E 2.0)
for mattplats AMD AM3:
AMD 890FX (x16 + x16, PCI-E 2.0)
AMD 890GX (x8 + x8, PCI-E 2.0)
AMD 790X (x8 + x8, PCI-E 2.0)
AMD 790GX (x8 + x8, PCI-E 2.0)
for mattplats Intel LGA2011:
Intel X79 (x16 + x16, PCI-E 3.0)
for motherboards under Intel LGA1366:
Intel X58 (x16 + x16, PCI-E 2.0)
for mattplats Intel LGA1156:
Intel P55 (x8 + x8, PCI-E 2.0)
* Here also the processor choice is important, CrossFireX is ONLY available on Lynnfield processors (i5-7xx, i7-8xx). On Clarkdale processors (i3-5xx, i5-6xx, Pentium) - IT IS IMPOSSIBLE.
for motherboards under Intel LGA1155:
Intel P67 (x8 + x8, PCI-E 2.0)
Intel Z68 (x8 + x8, PCI-E 2.0)
* It should be noted that math. boards on Intel P55 / P67 / Z68 chipsets:
1) if there is an additional chip nForce 200 support the scheme x16 + x16
2) can only support the circuit x16 + x4
for mattplats AMD AM2:
AMD 580X (x16 + x16, PCI-E 1.1)
AMD 790X (x8 + x8, PCI-E 2.0)
AMD 790GX (x8 + x8, PCI-E 2.0)
AMD 790FX (x16 + x16, PCI-E 2.0)
for mattplats Intel LGA775:
Intel 975X (x8 + x8, PCI-E 1.1)
Intel X38 (x16 + x16, PCI-E 2.0)
Intel P45 (x8 + x8, PCI-E 2.0)
Intel X48 (x16 + x16, PCI-E 2.0)
Hardcore players do not sleep at night, thinking about how to increase the performance of their computer, so that the game world appears before them in all the glory of the maximum graphics settings. For this, some buy an expensive top-end video card, others buy several budget video cards and combine them with the help of sLI technology or CrossFireX. What is more expedient and more effective? What increase in the performance of the video game is given by two budget video cards in SLI and CrossFireX modes in comparison with one top-end?
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One video card versus two
Let's take an average player who has one of the new video cards, for example Radeon HD 7950. What happens to the performance if you use the second same video card in combination with it crossFire technology? Testing in a benchmark from Futuremark shows: alone the HD 7950 issues 34.9 FPS, two such cards, the HD 7950 CrossFireX - 69.9 FPS (at a resolution of 1024 by 768), or 5.8 FPS and 11.6 FPS respectively at a resolution 2560 to 1600. The Unigine Heaven 2.0 test shows in the resolution of 1024 by 768: HD 7950 in one copy - 108.6 FPS, in a combination of two - 163.9 FPS, or at 2560 for 1600 - 39.2 FPS and 77.8 FPS, respectively. As can be seen from these tests, two video cards give a performance gain of almost double as compared to one. It can be argued that for $ 500 (the average price video card Radeon HD 7950 now 250 - 300 dollars) is quite a worthy solution for most games. It's worth noting that AMD likes to release new video cards with "raw" drivers, so some games, for example Elder Scrolls: Skyrim, Battlefield 3 may not be displayed as nicely as they should.
Two SLI-integrated video cards
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CrossFireX and SLI
AMD's CrossFireX technology is essentially similar to NVIDIA's SLI (Scan Line Interleave), which both serve to combine several video cards to process 3D images. The first promises an average performance increase depending on the resolution and model of the map by 70-100%, the second - in 2 times.
Both technologies require a special motherboard, at least with 2 x PCI Express x16 / 2.0 / 2.1 connectors, a powerful power supply - more than 500 watts and a smart multi-core processor. Video cards are needed in one series, the models can be different (on different chips). The speed of the entire system will be determined by the core of the least productive of the cards. To connect video cards you need special flexible bridges, the software was also used before, when data transfer was done through the PCI Express bus, and the drivers were interfaced with video cards, but the loss of performance of this method compared to the physical was 10-15%. The latest models of video cards can not unite at all. Using CrossFireX and SLI technologies, it is possible to combine up to 4 video cards.
The image using several GPUs is built in several ways. The first is Scissor (CrossFireX) or Split Frame Rendering (NVIDIA), in which different video cards process different parts of the image, not always equal. Minus this mode - the problem of smoothing at the junction of parts of the image.
The second mode is SuperTiling (only CrossFireX), when the picture is divided into equal squares, the load on the video cards is distributed approximately equally. The disadvantage is the uneven processing of the graphic and geometric components of the frame.
Alternative Frame Rendering - used by AMD and NVIDIA. Video cards process frames in turn, the pixels and the geometric component of the frame are calculated together, but because of the unequal characteristics of frames, the image can be "frozen".
SuperAA (CrossFireX) or SLI AA (NVIDIA) - this method is aimed at improving the quality of the picture more than improving performance. Two video cards draw one image with different anti-aliasing modes, the final picture is generated later.
It's impossible to answer unambiguously, which is better than technology, CrossFireX or SLI. At the moment, the manufacturer of CrossFireX claims that soon it will be possible to work with all applications, including old games that did not react to the increase in the number of video cards. SLI does not provide such a guarantee. However, two technologies have recently been tested using the NVIDIA Frame Capture Analysis Tool (FCAT), which tests the number of "short" and missed frames that are not taken into account by conventional performance measurement systems in terms of frames per second. The results showed that the CrossFireX bundle usually contains more skipped and "shorter" frames than SLI NVIDIA. While there is no reliable data, will the average gamer notice these differences.
SLI Bridge
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Analysis of bundles of two video cards and one top-up showed that the bundle is approaching in efficiency or superior to the top one. Thus, the pair HD 7850 exceeds the HD 7970 GHz Edition (almost the same level two cards HD 7790 worked). And two GTX 650 Ti BOOST beat the result of the GTX 680 (NVIDIA), the bundle from the GTX 660 also matched the performance to the GTX 780. This is the data for most games, in the game Batman: Arkham City, the CrossFireX pair does not work at all, and at the resolution of 1920x1080 two GTXs 660 inferior to one GTX 770. The cost of top cards can be up to 25,000 rubles, a bunch of two older ones will cost less without losing performance. On the other hand, a motherboard with CrossFireX or SLI modes is more expensive than a traditional one, a powerful power supply is also not a cheap one, if you add electricity costs to this, it turns out that the system on several video cards is not much cheaper, and maybe even more expensive system on one top-end video card. By the way, older graphics cards may not support DirectX 11th version, which also affects the quality of game graphics.
The use of the CrossFireX or SLI modes is justified in modern computer games with high requirements for graphics adapters and support for DirectX 11, such as Crysis Warhead, Metro 2033, Crysis 2, Far Cry 3, Crysis 3, Battlefield 3, Batman: Arkham City, Dirt Showdown. As for older games, paying more for a minor performance increase, which may not be visible to the user at all, makes no sense.
DirectX 11
Video cards are hardware technologies, but one "iron" is not enough. In order for the game to work fully, you need also a special software. In order for the game to be compatible with Windows, the game engine DirectX is put. 11 version is designed specifically for Windows 7, with even more modern Windows 8 comes DirectX 11.1.
Compared with previous versions technology, low-level support is available in the eleventh operating system and hardware, multi-thread processing has improved significantly. Now, advanced hardware image processing for tessellation is possible, three additional steps are used for this. Significantly improved texture compression. The 11th version has a built-in 5th shader model, which uses a lot of object-oriented concepts, you can easily solve problems related to the nature of shaders with advanced interfaces, polymorphism and additional objects.
© bukentagen
CrossFire is ATI's multi-GPU technology (now AMD's unit), which allows you to merge several Radeons to work on building a single 3D image.
The initial implementation of this technology (for the X800 and X1800 series chipsets) meant using a so-called "master card" and an external Y-shaped cable with a special chip that combines the two image fragments of the image into a single picture. However, this development has not been developed, and in the future ATI, like nVidia in its technology, began to use external bridges to exchange information between the maps integrated into the map array.
A prerequisite for combining two or more cards into an array (currently up to four GPUs, that is, it is possible to combine four uniprocessor cards or two dual-processor cards) is the belonging of video cards to one generation, for example, you can combine 4870X2 with 4870 or 4830 with 4870 , but to combine, say, Radeon X1950 with HD3850 does not work.
The modern version of CrossFire technology is officially called CrossFireX, sometimes CrossFire for convenience is reduced to "CF" (do not confuse with CompactFlash).
The combination of discrete (separate) with the built-in chipset is called Hybrid CrossFire and is accompanied by a number of additional limitations, this technology is dedicated.
When you combine maps into an array, each works with its copy of a set of textures and geometric data, so the actual amount of video memory is equal to the smallest amount of video memory available to each of the working video processors, that is, if you combine two cards with video memory sizes of 512 MB and 256 MB we get an effective amount of video memory in 256MB.
The same feature applies to video cards built on the basis of two video processors (identified by the suffix "X2" in the title), with the total amount of video memory declared, in fact, such a card is the equivalent of a card with half the amount of video memory and is appropriately recognized in 3D applications.
Unlike nVidia Technologies SLI, CrossFire does not impose strict requirements on the chipset manufacturer, so to combine several aTI graphics cards Radeon is theoretically suitable for the chipset of any manufacturer (even nVidia) with a suitable set of slots, but in practice this configuration can be optimally collected on specially designed Intel or AMD chipsets (depending on the processor used), however, it is necessary to pay attention to the following factors:
- The resulting performance of an array of video cards is maximum when each of the video cards included in it is connected to the chipset with the maximum possible number of PCI-E lines for it, i.e. uses a full-fledged PCI-E 16x slot. The presence of two such slots is typical for motherboardsah on the "top" chipsets - Intel X38 / X48 / X58, AMD 790FX, etc.
Therefore, if the CF system is assembled on the basis of "top" video cards like the Radeon HD4890, then the use of such motherboards is desirable (for maximum performance), and if the combination of two dual-chip cards like 4870X2 is used, then it is necessary. - With the use of "popular" chipsets like Intel P35 / P45, which do not have enough PCI-E lines, a fatal speed drop occurs only when one of the video cards is installed in a PCI-E 16x slot with one line, when installed in a slot with four or eight lines speed compared with the "full" option falls not so much.
- CrossFire variants with three or four video processors show a real advantage over the same configurations with two video processors only in "superheavy" modes (large, 1680X1050 and higher, resolution with FSAA enabled), and not in all games.
