Multi-GPU Performance

Crysis

NVIDIA's own multi-GPU solution outperformed the GeForce GTX 280 when it launched, so it is not too surprising to see the Radeon HD 4870 in CrossFire mode doing the same. If AMD can put two of these things on a single card it will have a viable competitor for the GTX 280 as well as the GX2.


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Call of Duty 4

AMD's architecture did very well under Call of Duty 4 in the single-card tests, with a single Radeon HD 4870 performing better than a GeForce GTX 260. The scaling from one to two cards is beyond perfect in CoD4, the reason being that we test on two different platforms (Intel X48 for CrossFire, NVIDIA 790i for all single-cards), the end result is a rare case where two of AMD's $300 cards actually outperform two of NVIDIA's $650 cards. By no means is it the norm, but it is a testament to the strength of AMD's RV770 GPU.


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Enemy Territory: Quake Wars

CrossFire continues to scale poorly in Quake Wars, while NVIDIA's GeForce GTX 280 SLI completely dominates the charts here. The 4870 CF performance isn't terrible, it's actually in line with where it should be (2 x $300 cards are about as fast as 1 x $650 card).


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Oblivion Multi-GPU Performance in Assassin's Creed, Oblivion, The Witcher & Bioshock
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  • DerekWilson - Wednesday, June 25, 2008 - link

    it looks like the witcher hits an artificial 72fps barrier ... not sure why as we are running 60hz displays, but that's our best guess. vsync is disabled, so it is likely a software issue.
  • JarredWalton - Wednesday, June 25, 2008 - link

    Again, try faster CPUs to verify whether you are game limited or if there is a different bottleneck. The Witcher has a lot of stuff going on graphically that might limit frame rates to 70-75 FPS without a 4GHz Core 2 Duo/Quad chip.
  • chizow - Wednesday, June 25, 2008 - link

    It looks like there seems to be a lot of this going on in the high-end, with GT200, multi-GPU and even RV770 chips hitting FPS caps. In some titles, are you guys using Vsync? I saw Assassin's Creed was frame capped, is there a way to remove the cap like there is with UE3.0 games? It just seems like a lot of the results are very flat as you move across resolutions, even at higher resolutions like 16x10 and 19x12.

    Another thing I noticed was that multi-GPU seems to avoid some of this frame capping but the single-GPUs all still hit a wall around the same FPS.

    Anyways, 4870 looks to be a great part, wondering if there will be a 1GB variant and if it will have any impact on performance.
  • DerekWilson - Wednesday, June 25, 2008 - link

    the only test i know where the multi-gpu cards get past a frame limit is oblivion.

    we always run with vsync disabled in games.

    we tend not to try forcing it off in the driver as interestingly that decrease performance in situations where it isn't needed.

    we do force off where we can, but assassins creed is limiting the frame rate in absentia of vsync.

    not sure about higher memory variants ... gddr5 is still pretty new, and density might not be high enough to hit that. The 4870 does have 16 memory chips on it for its 256-bit memory bus, so space might be an issue too ...
  • JarredWalton - Wednesday, June 25, 2008 - link

    Um, Derek... http://www.anandtech.com/video/showdoc.aspx?i=3320...">I think you're CPU/platform limited in Assassin's Creed. You'll certainly need something faster than 3.2GHz to get much above 63FPS in my experience. Try overclocking to 4.0GHz and see what happens.
  • weevil - Wednesday, June 25, 2008 - link

    I didnt see the heat or noise benchmarks?
  • gwynethgh - Wednesday, June 25, 2008 - link

    No info from Anandtech on heat or noise. The info on the 4870 is most needed as most reviews indicate the 4850 with the single slot design/cooler runs very hot. Does the two slot design pay off in better cooling, is it quiet?
  • DerekWilson - Wednesday, June 25, 2008 - link

    a quick not really well controlled tests shows the 4850 and 4870 to be on par in terms of heat ... but i can't really go more into it right now.

    the thing is quiet under normal operation but it spins up to a fairly decent level at about 84 degrees. at full speed (which can be heard when the system powers up or under ungodly load and ambient heat conditions) it sounds insanely loud.
  • legoman666 - Wednesday, June 25, 2008 - link

    I don't see the AA comparisons. There is no info on the heat or noise either.
  • DerekWilson - Wednesday, June 25, 2008 - link

    the aa comparison page had a problem with nested quotes in some cases in combination with some google ads on firefox (though it worked in safari ie and opera) ...

    this has been fixed ...

    for heat and noise our commentary is up, but we don't have any quantitative data here ... we just had so much else to pack into the review that we didn't quite get testing done here.

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