Applications of GF100’s Compute Hardware

Last but certainly not least are the changes to gaming afforded by the improved compute/shader hardware. NVIDIA believes that by announcing the compute abilities so far ahead of the gaming abilities of the GF100, that potential customers have gotten the wrong idea about NVIDIA’s direction. Certainly they’re increasing their focus on the GPGPU market, but as they’re trying their hardest to point out, most of that compute hardware has a use in gaming too.

Much of this is straightforward: all of the compute hardware is what processes the pixel and vertex shader commands, so the additional CUDA cores in the GF100 give it much more shader power than the GT200. We also have DirectCompute, which can use the compute hardware to quickly do some things that couldn’t be done quickly via shader code, such as Self Shadowing Ambient Occlusion in games like Battleforge, or to take an NVIDIA example, the depth-of-field effect in Metro 2033.

Perhaps the single biggest improvement for gaming that comes from NVIDIA’s changes to the compute hardware are the benefits afforded to compute-like tasks for gaming. PhysX plays a big part here, as along with DirectCompute it’s going to be one of the biggest uses of compute abilities when it comes to gaming.

NVIDIA is heavily promoting the idea that GF100’s concurrent kernels and fast context switching abilities are going to be of significant benefit here. With concurrent kernels, different PhysX simulations can start without waiting for other SMs to complete the previous simulation. With fast context switching, the GPU can switch from rendering to PhysX and back again while wasting less time on the context switch itself. The result is that there’s going to be less overhead in using the compute abilities of GF100 during gaming, be it for PhysX, Bullet Physics, or DirectCompute.

NVIDIA is big on pushing specific examples here in order to entice developers in to using these abilities, and a number of demo programs will be released along with GF100 cards to showcase these abilities. Most interesting among these is a ray tracing demo that NVIDIA is showing off. Ray tracing is something even G80 could do (albeit slowly) but we find this an interesting way for NVIDIA to go since promoting ray tracing puts them in direct competition with Intel, who has been showing off ray tracing demos running on CPUs for years. Ray tracing nullifies NVIDIA’s experience in rasterization, so to promote its use is one of the riskier things they can do in the long-term.


NVIDIA's car ray tracing demo

At any rate, the demo program they are showing off is a hybrid program that showcases the use of both rasterization and ray tracing for rendering a car. As we already know from the original Fermi introduction, GF100 is supposed to be much faster than GT200 at ray tracing, thanks in large part due to the L1 cache architecture of GF100. The demo we saw of a GF100 card next to a GT200 card had the GF100 card performing roughly 3x as well as the GT200 card. This specific demo still runs at less than a frame per second (0.63 on the GF100 card) so it’s by no means true real-time ray tracing, but it’s getting faster all the time. For lower quality ray tracing, certainly this would be doable in real-time.


Dark Void's turbulence in action

NVIDIA is also showing off several other demos of compute for gaming, including a PhysX fluid simulation, the new PhysX APEX turbulence effect on Dark Void, and an AI path finding simulation that we did not have a chance to see. Ultimately PhysX is still NVIDIA’s bigger carrot for consumers, while the rest of this is to entice developers to make use of the compute hardware through whatever means they’d like (PhysX, OpenCL, DirectCompute). Outside of PhysX, heavy use of the GPU compute abilities is still going to be some time off.

Better Image Quality: CSAA & TMAA 3D Vision Surround: NVIDIA’s Eyefinity
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  • dentatus - Monday, January 18, 2010 - link

    " Im sure ATi could pull out the biggest, most expensive, hottest and fastest card in the world"- they have, its called the radeon HD5970.

    Really, in my Australia, the ATI DX11 hardware represents nothing close to value. The "biggest, most expensive, hottest and fastest card in the world" a.k.a HD5970 weighs in at a ridiculous AUD 1150. In the meantime the HD5850 jumped up from AUD 350 to AUD 450 on average here.

    The "smaller, more affordable, better value" line I was used to associating with ATI went out the window the minute their hardware didn't have to compete with nVidia DX11 hardware.

    Really, I'm not buying any new hardware until there's some viable alternatives at the top and some competition to burst ATI's pricing bubble. That's why it'd be good to see GF100 make a "G80" impression.
  • mcnabney - Monday, January 18, 2010 - link

    You have no idea what a market economy is.

    If demand outstrips supply prices WILL go up. They have to.
  • nafhan - Monday, January 18, 2010 - link

    It's mentioned in the article, but nvidia being late to market is why prices on ATI's cards are high. Based on transistor count, etc. There's plenty of room for ATI to drop prices once they have some competition.
  • Griswold - Wednesday, January 20, 2010 - link

    And thats where the article is dead wrong. For the most part, the ridiculous prices were dictated by low supply vs. high demand. Now, we finally arrived at decent supply vs. high demand and prices are dropping. The next stage may be good supply vs normal demand. That, and no second earlier, is when AMD themselves could willingly start price gouging due to no competition.

    However, the situation will be like this long after Thermi launched for the simple reason, that there is no reason to believe that Thermi wont have yield issues for quite some time after they have been sorted out for AMD - its the size of chipzilla that will give it a rough time for the first couple of months, regardless of its capabilities.
  • chizow - Monday, January 18, 2010 - link

    I'm sure ATI would've if they could've instead of settling for 2nd place most of the past 3 years, but GF100 isn't just about the performance crown, its clearly setting the table for future variants based on its design changes for a broader target audience (think G92).
  • bupkus - Monday, January 18, 2010 - link

    So why does NVIDIA want so much geometry performance? Because with tessellation, it allows them to take the same assets from the same games as AMD and generate something that will look better. With more geometry power, NVIDIA can use tessellation and displacement mapping to generate more complex characters, objects, and scenery than AMD can at the same level of performance. And this is why NVIDIA has 16 PolyMorph Engines and 4 Raster Engines, because they need a lot of hardware to generate and process that much geometry.

    Are you saying that ATI's viability and funding resources for R&D are not supported by the majority of sales which traditionally fall into the lower priced hardware which btw requires smaller and cheaper GPUs?
  • Targon - Wednesday, January 20, 2010 - link

    Why do people not understand that with a six month lead in the DX11 arena, AMD/ATI will be able to come out with a refresh card that could easily exceed what Fermi ends up being? Remember, AMD has been dealing with the TSMC issues for longer, and by the time Fermi comes out, the production problems SHOULD be done. Now, how long do you think it will take to work the kinks out of Fermi? How about product availability(something AMD has been dealing with for the past few months). Just because a product is released does NOT mean you will be able to find it for sale.

    The refresh from AMD could also mean that in addition to a faster part, it will also be cheaper. So while the 5870 is selling for $400 today, it may be down to $300 by the time Fermi is finally available for sale, with the refresh part(same performance as Fermi) available for $400. Hmmm, same performance for $100 less, and with no games available to take advantage of any improved image quality of Fermi, you see a better deal with the AMD part. We also don't know what the performance will be from the refresh from AMD, so a lot of this needs to take a wait and see approach.

    We have also seen that Fermi is CLEARLY not even available for some leaked information on the performance, which implies that it may be six MORE months before the card is really ready. Showing a demo isn't the same as letting reviewers tinker with the part themselves. Really, if it will be available for purchase in March, then shouldn't it be ready NOW, since it will take weeks to go from ready to shipping(packaging and such)?

    AMD is winning this round, and they will be in the position where developers will have been using their cards for development since NVIDIA clearly can't. AMD will also be able to make SURE that their cards are the dominant DX11 cards as a result.

  • Targon - Wednesday, January 20, 2010 - link

    Why do people not understand that with a six month lead in the DX11 arena, AMD/ATI will be able to come out with a refresh card that could easily exceed what Fermi ends up being? Remember, AMD has been dealing with the TSMC issues for longer, and by the time Fermi comes out, the production problems SHOULD be done. Now, how long do you think it will take to work the kinks out of Fermi? How about product availability(something AMD has been dealing with for the past few months). Just because a product is released does NOT mean you will be able to find it for sale.

    The refresh from AMD could also mean that in addition to a faster part, it will also be cheaper. So while the 5870 is selling for $400 today, it may be down to $300 by the time Fermi is finally available for sale, with the refresh part(same performance as Fermi) available for $400. Hmmm, same performance for $100 less, and with no games available to take advantage of any improved image quality of Fermi, you see a better deal with the AMD part. We also don't know what the performance will be from the refresh from AMD, so a lot of this needs to take a wait and see approach.

    We have also seen that Fermi is CLEARLY not even available for some leaked information on the performance, which implies that it may be six MORE months before the card is really ready. Showing a demo isn't the same as letting reviewers tinker with the part themselves. Really, if it will be available for purchase in March, then shouldn't it be ready NOW, since it will take weeks to go from ready to shipping(packaging and such)?

    AMD is winning this round, and they will be in the position where developers will have been using their cards for development since NVIDIA clearly can't. AMD will also be able to make SURE that their cards are the dominant DX11 cards as a result.

  • chizow - Monday, January 18, 2010 - link

    @bupkus, no, but I can see a monster strawman coming from a mile away.
  • Calin - Monday, January 18, 2010 - link

    "Because with tessellation, it allows them to take the same assets from the same games as AMD and generate something that will look better"

    No it won't.
    If the game will ship with the "high resolution" displacement mappings, NVidia could make use of them (and AMD might not, because of the geometry power involved). If the game won't ship with the "high resolution" displacement maps to use for tesselation, then NVidia will only have a lot of geometry power going to waste, and the same graphical quality as AMD is having.

    Remember that in big graphic game engines, there are multiple "video paths" for multiple GPU's - DirectX 8, DirectX 9, DirectX 10, and NVidia and AMD both have optimised execution paths.

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