Compute Performance

Moving on from our look at gaming performance, we have our customary look at compute performance. With AMD’s architectural changes from the 5000 series to the 6000 series, focusing particularly on compute performance, this can help define the 6990 compared to the 5970. However at the same time, neither benchmark here benefits from the dual-GPU design of the 6990 very much.

Our first compute benchmark comes from Civilization V, which uses DirectCompute to decompress textures on the fly. Civ V includes a sub-benchmark that exclusively tests the speed of their texture decompression algorithm by repeatedly decompressing the textures required for one of the game’s leader scenes.

New as of Catalyst 11.4, AMD’s performance in our Civilization V DirectCompute benchmark now scales with CrossFire at least marginally. This leads to the 6990 leaping ahead of the 6970, however the Cayman architecture/compiler still looks to be sub-optimal for this test. The 5970 has a 10% lead even with its core clock disadvantage. This also lets NVIDIA and their Fermi architecture establish a solid lead over the 6990, even without the benefit of SLI scaling.

Our second GPU compute benchmark is SmallLuxGPU, the GPU ray tracing branch of the open source LuxRender renderer. While it’s still in beta, SmallLuxGPU recently hit a milestone by implementing a complete ray tracing engine in OpenCL, allowing them to fully offload the process to the GPU. It’s this ray tracing engine we’re testing.

There’s no CrossFire scaling to speak of in SmallLuxGPU, so this test is all about the performance of GPU1, and its shader/compute performance at that. At default clocks this leads to the 6990 slightly trailing the 6970, while overclocked this leads to perfect parity with it. Unfortunately for AMD this is a test where NVIDIA’s focus on compute performance has really paid off; coupled with the lack of CF scaling and even a $240 GTX 560 Ti can edge out the $700 6990.

Ultimately the take-away from this is that for most desktop GPU computing workloads, the benefit of multiple GPU cores is still unrealized. As a result the 6990 shines as a gaming card, but is out of its element as a GPU computing card unless you have an embarrassingly parallel task to feed it.

Wolfenstein Power, Temperature, and Noise: How Loud Can One Card Get?
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  • Ryan Smith - Tuesday, March 8, 2011 - link

    Yes, using the LateGameView benchmark. Like any other benchmark it's not a perfect representation of all scenarios, but generally speaking it's a reasonable recreation of a game many turns in with a large number of units.
  • jabber - Tuesday, March 8, 2011 - link

    All cards at this level are niche. Very few of us have that much to splash on one component.

    I find it amusing that most of the folks here going "oh wow thats too noisy/power hungry/slow etc. so I wont be buying!", will just then load up Crysis on their 5770/GTX460 equipped PCs.

    Note to 95% of you reading this article...this card isnt/wasnt designed for you.
  • araczynski - Tuesday, March 8, 2011 - link

    nice, but it sounds like the 6950CF owns the bang/$ award, this thing is too little for too much $/headache.
  • araczynski - Tuesday, March 8, 2011 - link

    then again my 4850CF/E8500 system just played dragon age 2 demo at 1920x1200 with absolutely no problems, so have no reason to upgrade just yet, still.
  • Gainward - Tuesday, March 8, 2011 - link

    I also just wanted to touch on that comment. Whilst these cards seem excessive to some you have to remember that @ this moment in time they are as I dub it the veyron moment like others in the past the concorde moment. They might not be for most people practical but to its like me saying to my team, look lets see what we can do. Not only that but having the crown of fastest single card (agreed single card but multi gpu) goes a long way to brand loyalty and advertising.
    An example I like to use is the GTX 560. Its a fantastic card and in many ways better… hang with me a second. In terms of actual raw power you get for sub £200 is incredible also factor in its quiet and wont eat through your electricity like a moth through primark. But…. to not produce these high end cards would be criminal. We need people to keep pushing as hard and fast (that sounds so wrong) at the the boundaries(agreed quite crudely in the 6990 case but hey I dont sit in either camp just wait a few days for the 590 for brute but crude).
    with the reduction in nm to 28 the power consumption and heat will be brought down further (dont need pointing out here that a lot of factors at play here it was just a generalisation) but sure we could see just as big and hot cards within practical reason.
    I would not say out of hand I would say its progress and with progress we can lear
  • Figaro56 - Tuesday, March 8, 2011 - link

    Roger that.
  • JimmiG - Tuesday, March 8, 2011 - link

    "Water cooled 6990s will be worth their weight in gold."

    They'll probably cost about that too...
  • smigs22 - Tuesday, March 8, 2011 - link

    The r6990 stands out as a massive single card leader. The 6950CF offers far better price/perfomance with potential for 6970CF performance through BIOS flashing.

    Maybe you should break up some of the charts to show only single cards configurations (for those with motherboards lacking full/partial SLI/CF support).

    It will be interesting to see how enabled & what clocks the gf590 will arrive at, in order to keep its power-draw & temps down to reasonable levels??

    I wonder if someone would place a carbon tax on these bad boys....lol
  • Figaro56 - Tuesday, March 8, 2011 - link

    The would have done this, but there is a cryo cooled case interior on the market yet.
  • IceDread - Tuesday, March 8, 2011 - link

    If the card would have come with water cooling option or something like that, then it would have been a great product.

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