ATI's Multi-GPU Solution: CrossFire
by Anand Lal Shimpi & Derek Wilson on May 30, 2005 9:00 PM EST- Posted in
- GPUs
ATI's Answer to SLI: CrossFire (The Motherboard)
As with NVIDIA's multi-card graphics solution launch, ATI is bringing to market their Radeon Xpress 200 CrossFire-Edition chipset. Motherboards based around CrossFire will feature 2 physical PCI Express x16 slots with x8 electrical connections. If the motherboard manufacturer implements it, the second PCI Express slot does not require a selector card and can be used with any other x8 or lower device. When only one graphics card is installed, the BIOS is capable of reconfiguring dynamically the number of lanes that the PCI Express slots run, provided that the motherboard includes support for this feature. Some vendors will sell motherboards set up just like NVIDIA's solutions (more on that later).Limiting the cards to only 2 x8 PCI Express connections may be a bottleneck if a game makes heavy use of the bus. Of course, we will run into similar issues with NVIDIA's solutions when paired with games that are PCI Express intensive. Unfortunately, as none yet exist, testing of this category of application is very difficult.
The Xpress 200 CrossFire-Edition is also capable of supporting integrated graphics. One excellent feature of the Xpress 200 CrossFire system is that, on boards where the OEM has included integrated graphics and two display outputs, 6 displays can be driven simultaneously (two from the integrated graphics, two from the standard Radeon, and two from the CrossFire card). Having the ability to support so many displays, while also offering the speed up of multiple GPUs is quite compelling; especially if ATI allows multiple GPU operation alongside multiple display support.
The need to buy a new motherboard in order to upgrade to a multiple GPU solution will likely keep some people from upgrading, but NVIDIA's solutions have the same problem. The fact that CrossFire is only being offered for the X800 and X850 series does limit the upgrade potential at this point. We have been recommending against using multi GPU solutions as an upgrade path option, but offering that freedom is still a plus.
ATI has given us the indication that CrossFire should work on Intel Chipsets as well as their own. This could give new life to those Intel designs originally targeted at SLI. Though not explicitly stating that CrossFire will work in an NVIDIA SLI board, it definitely seems possible. From an adoption/compatibility standpoint, ATI is certainly "evaluating other options".
There is also no physical reason why SLI cards could not work in an ATI Xpress CrossFire-Edition motherboard. The only thing that should stand in the way of this combination is NVIDIA's driver support. With the price premium that NVIDIA charges for their SLI chipset, it is clear that they want to discourage users from going another route. As they had owned the market on multi GPU solutions until now, that was an option. Now that ATI is throwing some competition in the ring, it would not be smart to exclude potential customers from using SLI just because of their motherboard choice.
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Pollock - Tuesday, May 31, 2005 - link
Looks interesting to me, at least so far. I'll agree that we still have to see how things turn out.Eug - Tuesday, May 31, 2005 - link
Crossfire? Meh. About 0.1% of the population will buy dual GPU setups. Crossfire is essentially just a marketecture exercise.The really interesting part is the H.264 acceleration, which will have much, much more impact for the general computing world than Crossfire.
nitromullet - Tuesday, May 31, 2005 - link
Interesting... They gave AT stock photos of a Intel based motherboard, but the benchmarking was done on an AMD rig. Anyone know if the chipset(s) support Athlon X2 and/or Pentium D?To the person that mentioned that Doom3 is not a good benchmark for ATi: My guess is that Doom3 is probably a good benchmark to use for this purpose. ATi is most assuredly GPU bound in Doom3, so any increase in GPU power will yield a positive result. Whereas in HL2 where ATi has really strong single performance, I would imgaine that the Crossfire rig is CPU lmited, so there is not as drastic of an increase.
Either way, Crossfire looks to be pretty interesting. Can't wait to see some in depth benches and some screenies of the super AA modes.
A request to AT: how about some benches in standard and widescreen resolutions. I know that SLI had compatibility issues with widescreen in the past, and it would be nice to know if those are still around and/or if Crossfire also suffers from this.
Nice article, especially with the limitation of not being able to run a full suite of benchmarks.
jiulemoigt - Tuesday, May 31, 2005 - link
So what about the fact the new mode does not work in OpenGL? I happened to love playing with directX api but knowing that half the engines will not be able to use the new filtering? I like the idea of the new chip they are putting on the board, I'm disguested most of the ATI stuff is marketing not hardware I have to develope for the hardware in peoples machines and the baises that people have toward tech and i'm getting sick of finding a new way of doing something not being able to use it because it only works on nvidia and ati bashes till they sorta get it working then they claim it's the best thing since sliced bread. Lets try and force nvidia and ati marking people to focus on what is there not what there side has.DerekWilson - Tuesday, May 31, 2005 - link
I suppose we should add a disclaimer to the statement about Super AA working with everything ...From what we *hear* from ATI, all games will work with CrossFire. This means that all games will work with at least one of the performance or quality modes. Even if a game doesn't work under AFR, split, or supertiling, it should work with Super AA ...
But we will have to test compatibility for ourselves.
Derek Wilson
porkster - Tuesday, May 31, 2005 - link
I can't see why they can't just use one PCIe card with a extra socket. Wheny ou ened to upgrade for more power then you buy just the chip and put the extra GPU chip in the socket to make a dual graphics card.SLI is a waste of time in that it's a direction in motherboard layout that isn't going to last, it's a dead end road for the future. So rather than was all the time developing cards that work in tandom, make the card to work with more GPU chip ont he same daughter board.
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AdamK47 3DS - Tuesday, May 31, 2005 - link
"all games will be accelerated under any Super AA mode"I hope Anandtech isn't pulling my leg here. I'd love to see Halo PC or Splinter Cell using AA. Currently no form of multisampling allows AA in these games. There are probably more games out there that have the same multisampling limitation, but these are the two I know of.
matthieuusa - Tuesday, May 31, 2005 - link
And should I had that investors seems to feel like ATI is taking its place back. NVDIA stocks already dropped 59 cents witht the announcement of ATI crossfire and R520 playback display...#37: totally agree, it is going to be a nice fight! If R520 is overall better than the G70, NVDIA will have to worry and counter it as fast as they can (which is going to be great for us).
matthieuusa - Tuesday, May 31, 2005 - link
I agree with #35. It is a little early to know which solution will be considered the best, even if it seems that ATI is bringing sone very interesting features along with their Crossfire. Not everybody care about playing Doom3 at 110 fps. I rather play at 80fps and have all the eye candies, and even more, since they are going to propose heavier FSAA.Since SLI and Crossfire will probably come to be close, it is going to see which one of the r520 and g70 will be the fastest with the most interesting features. But if ATI did as good with the R520 as they seem to have done with the Crossfire, they could take back the crown.
NVIDIA seems in hurry to put the G70 on the shelves, which seems kind of suspect, since there is are no real reasons to do so. They acually do have the most popular cards and the fastest configuration with SLI.
Did they heard about ATI R520 specs and fear to be at a disadvantage? Do they need two G70 to beat it?
Wait and See
#36 2PCI-E 8X -> that is exactly what SLI is right now with NVDIA.
Compositing Engine chip -> Do you remember the discussion about the PCI-E bridge implemented on GeForce 6 cards? Experience has shown no performance drop. Instead, in ATI's "SLI" solution, it seems even better since it is not part of the die -> less heat... It is not new to them, since there are using it in professionnals products
kyaku00x - Tuesday, May 31, 2005 - link
I think the next chipset king will be the one producing the best next-gen graphics cards. if NV70 is better performing than r520 then I wouldn't think that people are going to care about going ATI in the mobo department, but if r520>nv70, then nvidia may start losing the chipset market.this will be real interesting to watch, the first chipset war determined by graphics cards :P