ATI GPU help please |
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Questions and Answers : GPU applications : ATI GPU help please
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I apologize for what may (most likely are) be dumb questions... | |
| ID: 1273563 · | |
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Disregard the last computer, my home server. Apparently there's some issue between the video card/drivers, WinServer2008 and BOINC. For some reason BOINC isn't recognizing it as an OpenCL GPU. | |
| ID: 1273569 · | |
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That problem will most likely be the drivers. | |
| ID: 1273620 · | |
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I'm contemplating just installing Win7 on that machine just because of the driver issue with WinServer2008R2.
Obviously it looks like a memory problem, but the GPU has 1024MB onboard and the machine itself has 4gig RAM. I thought at first it may be a problem with the hybrid dual-GPU the machine came with that combined an on-motherboard GPU with the 4600 series card, but I disabled the on-board in bios. In the error it talks about max_kernel_wg_size, but the only other reference to wg I can find says "max WG size: 128" so I don't know if that's causing it to self-destruct and if so, how to change it. | |
| ID: 1273799 · | |
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The "WG" or workgroup size must be 256 or larger. If it says 128, your GPU cannot be used. At least that's the way it was when the app was being developed, so I believe this to be true unless someone else knows otherwise. | |
| ID: 1273818 · | |
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I have the same problem with my computer: | |
| ID: 1274106 · | |
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A patch would have to be written first. I do not believe one has been written. In fact, the ATi GPU application was written by a third party and was freely given to SETI@Home to use as a "stock" application (after rigorous testing was done to ensure that the application met the standards set by the SETI@Home team). | |
| ID: 1274111 · | |
This third party person (Raistmer, I believe) would have to write new code to support low workgroup GPUs. But his tasks show "Max work group size: 256" http://setiathome.berkeley.edu/result.php?resultid=2571256428 http://setiathome.berkeley.edu/result.php?resultid=2570688972 I don't know what "WARNING: patching required max_kernel_wg_size=64" means. I will try to PM Raistmer to direct him to this thread. The only other place I found max_kernel_wg_size (in 1 year period) is: http://setiathome.berkeley.edu/forum_thread.php?id=68675&postid=1258896#1258896 ____________ - ALF - "Find out what you don't do well ..... then don't do it!" :) | |
| ID: 1274256 · | |
I have the same problem with my computer: Previous reports were from low-end GPUs with max WG size of 128 and tasks were completed OK on those hosts in spite of this precaution warning. So it was leaved as is, but apparently not in all cases this precaution warning can be safely ignored. "patching" is done inside oclFFT kernel generation routine and means that after initial kernels generation routine discovered that kernels need change to be runnable on device. Perhaps, binary cache recives wrong kernel version in this situation. I will try to do fix for this issue but this can take some time. What to try right now: 1. To stop Ati GPU processing on affected host. It's easiest but least productive. 2. Try to recive more info about issue - is it binary cache connected or not: suspend all GPU tasks, go to project directory and delete all oclFFT*.bin files, unsuspend single GPU task and let it run or error, report outcome to server, give link to result. 3. If you prefer to stay on "Stock" path try to replace AP stock executable with r455 AP gpu opt file (via renaming). That build has no binary cache as far as I can recall and can be free from this issue. But it would be easier to download and run Lunatics installer. | |
| ID: 1274272 · | |
The reason why patching required in this case - HD4xxx family of ATi GPUs has no real local/shared memory (they have fast LDS memory but it doesn't meet OpenCL requirements for local memory so was never exposed to OpenCL runtime. OpenCL can't use all available hardware resources for these GPUs). It emulates this kind of memory via global GPU memory. Consequence of this (besides much longer shared memory access times and performance issues in kernels that uses shared memory) - workgroup size for kernel that uses shared/local memory can not exceed 1 wavefront size, i.e., 64. oclFFT kernels use local memory so their workgroup should be 64 even if GPU itself supports max WG size of 256. | |
| ID: 1274278 · | |
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I suspended the gpu tasks and deleted the oclFFT*.bin file and unsuspended gpu. | |
| ID: 1274757 · | |
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I had no luck with that solution either. | |
| ID: 1274868 · | |
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I have three HD 4650s and all of them have a workgroup size of 128 and won't crunch. I don't think you'll have any luck with that either. | |
| ID: 1274871 · | |
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Well, wife's machine is happy now using the stock BOINC ATI app with the HD5450 from my server. The server has the 4650 which won't do GPU, but driver issues with Windows Server 2008R2 prevented that anyway. | |
| ID: 1276879 · | |
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Just coming into this late and have recently installed a Radeon 4650 into my system which is a Core 2 duo on Windows XP home. | |
| ID: 1292906 · | |
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If BOINC isn't detecting a usable GPU, you'll need to make sure you're installing the OpenCL compatible drivers for Windows XP, of which the last version to support OpenCL for XP was Catalyst 12.1. | |
| ID: 1292913 · | |
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I would also ask whether you installed BOINC in protected mode. | |
| ID: 1293004 · | |
Questions and Answers : GPU applications : ATI GPU help please
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