Untrue. See Folding@Home, where GT200b stomps all over anything ATi has, including Hemlock. Math rate isn't the only factor in solving any problem, GPGPU or not.
The one and only Folding @ Home thread
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Untrue. See Folding@Home, where GT200b stomps all over anything ATi has, including Hemlock. Math rate isn't the only factor in solving any problem, GPGPU or not.
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Isn't that because it isn't optimized for ATI GPU's?
A choice on ATi's part, and an ironic one given the fact that F@H for GPUs began on ATi hardware.
But the fact still stands, therefore it's not a good comparison. And why is this a choice on ATI's part? Why don't the F@H people (are they still at Stanford?) optimize the ATI client?
I think that ATI have the hardware in cypress to compete. Its just the sofware that is lacking
It is a good comparison, because it's a real-world example. ATi chooses not to work with Pande Group to help optimize the F@H client for their hardware. Nvidia does the opposite, as is often the case.
Perhaps so, but previous ATi hardware is deficient as the F@H client often has to redo calculations just to ensure correctness, something that doesn't occur when running on NV hardware.
The core for Radeon has not been updated from the Brook+ codebase, while the NVIDIA code has been updated a once or twice with CUDA. There is no reason why OpenCL could not be employed and bring performance up significantly on AMD hardware.
We're discussing in the GPGPU forum the some of the performance differences that can be gained from going from Brook+ to OpenCL, as the graph here highlights.
The core need to move to OpenCL, we can't completely re-write their code. They have made indications that they will move that direction, but haven't done so yet.
Incorrect. That is something they decided to do due to the limiations with the early Book+ codebase. Remember, the code for the GPU2 client was designed for R600 class hardware and has not moved since then.
Pande Group is working on an OpenCL client, and once again here, the NV client is ahead of the ATi client because NV is working with Pande Group to make sure the code runs, and optimally at that. Latest rumors in the F@H community put the NV OpenCL client available a good 6 months before the ATi client.
Did NV need to "completely re-write" F@H to get such good performance? Whatever they did, they did it right, and willingly.
I'm having difficulty finding the link, but I read @ folding forum a quote (from 7im, I believe) that ATi hardware had to redo some calculations to ensure correctness and this was a big reason why it was slower than NV hardware.
Where's Mike Houston when you need him?
And thats not a "hardware" issue, from a hardware perspective NVIDIA's stuff is no different in this respect.
To Mintmasters point, though, this is a very contrived case due to the differences in the software base being used.
Doing some F@H myself, that's not exactly what I'd have liked to hear as one of your customers.
Just going by what I read on folding forum, which seemed to indicate a hardware deficiency.
Well as contrived as it may be, it's one of the biggest factors for me when purchasing a GPU, or GPUs as is the case since I own three high-end PCs with dedicated graphics cards. Further to the point, it is why, when I purchased a high-end graphics card in February '09, I went with a GTX 285 rather than anything ATi had on the market, and again in January and February of this year why I purchased two GTX 275s to upgrade my other two machines. As long as ATi continues to have inferior developer relations when compared to Nvidia, and as long as F@H is not important to them, I will continue to purchase NV hardware.
Sorry? Its their code, not ours! We don't re-write games for developers, do we!? We have dev rel, we assist and get can help optimise and there is no difference between game and stream apps there.
Well it's a good thing for wavey that this market consists of less than 10 people.
But this is because F@H places artificial limitations on AMD's client, not because of hardware.
Why should AMD have to hold developers hand on every little thing. It's up to the developers to write the bulk of the code. AMD is there to give advice and provide minor help on optimization.
First, the CUDA and the Brook clients use a different code base, different algorithms and calculate different classes of proteins, it's hard to make good comparisons on that base.
Furthermore the ATI version of Folding was developed with an ancient Brook release without support for local memory. AFAIK that is the reason it does actually twice the number of calculations as it is cheaper to redo it than to store it somewhere in memory and load it again later. Newer Brook releases support the local memory of RV770 GPUs, but Stanford never bothered to update their code. The scaling from RV670 -> RV770 -> RV870 ist extremely bad (virtually non-existent), not exactly a sign of an optimal and forward looking coding.
I guess this should not become a discussion of how AMD's devrel department works or should be working, so I won't say anything to those points.
True, but everything AMD produces is just a useless hunk without software. So maybe they should hold some more hands
Well it is the most popular GPGPU application...
There are client-specific work units but these don't differentiate between NV and ATi hardware, the same work unit runs on both. The algorithm may be different, but the workload is not, neither is the output.
GT200b is nearly twice as fast as G80, and GF100 is about 50% faster than GT200b, despite not having any optimizations in the client. ATi hardware only gains performance in F@H through clockspeed increases. Cypress is no faster than RV770 @ the same clockspeed, despite having twice the ALUs and better register/cache architecture for GPGPU.
Whatever the reason, ATi hardware does not scale in F@H, and NV hardware does.
Well it's a good thing for wavey that this market consists of less than 10 people.
if it's only ten people then you've got 20% of them right here between Carsten and myself I don't believe this is a fair characterization. I don't think Pande Group does less work on ATi GPUs because they want to.
They shouldn't have to, but there's a reason most popular PC games have TWIMTBP logos in them and tend to run better on NV hardware.