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Multicore CPUs :
"This computer has finished a daily quota of 32 tasks"
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Send message Joined: 26 Feb 14 Posts: 211 Credit: 4,496,324,562 RAC: 0 Level ![]() Scientific publications ![]() ![]() ![]() ![]() ![]() ![]() ![]()
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Can you give me an estimated runtime of these WUs to know how many of them to pack together? Don't know if this link will work but here's a list of my CPU tasks http://www.gpugrid.net/results.php?userid=103037&offset=0&show_names=0&state=0&appid=30 edit.. I run 4 threads per work unit. Currently only 1 work unit per machine. 2 machines. |
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Send message Joined: 28 Jul 12 Posts: 819 Credit: 1,591,285,971 RAC: 0 Level ![]() Scientific publications ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
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Here is my i7-8700 http://www.gpugrid.net/results.php?hostid=475515 They were often less than 10 minutes each, and I was running three at a time. You could pack 10 of them together insofar as I am concerned (or at least 4). |
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Send message Joined: 3 Jul 18 Posts: 22 Credit: 2,758,801 RAC: 0 Level ![]() Scientific publications
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Very interesting comparison of run times. Running intel myself, Ryzen seems to struggle. Tasks take approx 10mins now but I'd prefer to crunch tasks <60mins. |
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Send message Joined: 5 Mar 13 Posts: 348 Credit: 0 RAC: 0 Level ![]() Scientific publications ![]() |
Ok thanks for the reports! The problem is that the WU runtime scales quadratically to the number of electrons in the molecule so larger molecules will take longer. But I assume I can go at least 5x the current length for this batch. |
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Send message Joined: 28 Jul 12 Posts: 819 Credit: 1,591,285,971 RAC: 0 Level ![]() Scientific publications ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
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Running intel myself, Ryzen seems to struggle. My i7-8700 was running 4 cores per work unit, whereas my Ryzen 1700 was running only 2 cores per work unit. And the Ryzen has 16 virtual cores, while the i7-8700 has only 12, so you would expect more per core from the Intel. Still, I agree that Intel is a little faster, though not be a large amount. I would be comfortable using either or both. |
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Send message Joined: 3 Jul 18 Posts: 22 Credit: 2,758,801 RAC: 0 Level ![]() Scientific publications
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The following is largely anecdotal, but I've found that 4-core tasks are more efficient than to two 2-core tasks. After 1 hour, 4-cores had accumulated (slightly) more credit, which includes start up time for each task and so on. My CPU does not support Hyper Threading, but it might be worth a separate test, if you're looking for best efficiency. With more cores memory and disk through put seem especially relevant for QC. |
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Send message Joined: 28 Jul 12 Posts: 819 Credit: 1,591,285,971 RAC: 0 Level ![]() Scientific publications ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
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With more cores memory and disk through put seem especially relevant for QC. That could be, especially with the new work units. I think we all should test that if possible. Thanks. |
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Send message Joined: 26 Feb 14 Posts: 211 Credit: 4,496,324,562 RAC: 0 Level ![]() Scientific publications ![]() ![]() ![]() ![]() ![]() ![]() ![]()
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Ok thanks for the reports! The problem is that the WU runtime scales quadratically to the number of electrons in the molecule so larger molecules will take longer. But I assume I can go at least 5x the current length for this batch. So I just checked and see the CPU work units are running longer. Longest so far was 1800 seconds. Are these the new work units you were talking about. Still much shorter than a GPU task. No errors so far (looks around for wood to knock on)
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Send message Joined: 8 May 18 Posts: 190 Credit: 104,426,808 RAC: 0 Level ![]() Scientific publications
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I am getting errors on QC tasks "Disk limit exceeded". They are all SELE6. Tullio |
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Send message Joined: 26 Feb 14 Posts: 211 Credit: 4,496,324,562 RAC: 0 Level ![]() Scientific publications ![]() ![]() ![]() ![]() ![]() ![]() ![]()
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I'm starting to see those too. Just had 4 of them error out on my machine. |
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Send message Joined: 3 Jul 18 Posts: 22 Credit: 2,758,801 RAC: 0 Level ![]() Scientific publications
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+1 |
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Send message Joined: 8 May 18 Posts: 190 Credit: 104,426,808 RAC: 0 Level ![]() Scientific publications
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I am running SETI@home and Einstein@home on both Linux boxen and also on a Ulephone smartphone with Android 7.1.1, Atlas@home on my Windows 10 PC.Goodbye GPUGRID. Tullio |
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Send message Joined: 28 Jul 12 Posts: 819 Credit: 1,591,285,971 RAC: 0 Level ![]() Scientific publications ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
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The last three QC have all erred for me with "Disk usage limit exceeded" also. It is time to give it a rest until they can get it fixed, hopefully soon. |
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Send message Joined: 26 Feb 14 Posts: 211 Credit: 4,496,324,562 RAC: 0 Level ![]() Scientific publications ![]() ![]() ![]() ![]() ![]() ![]() ![]()
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The last three QC have all erred for me with "Disk usage limit exceeded" also. It is time to give it a rest until they can get it fixed, hopefully soon. Yes it appears to be getting worse. Almost all are erring out now. I say almost all, a half dozen have finished where previously they erred on other's machines.
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Send message Joined: 17 Feb 09 Posts: 91 Credit: 1,603,303,394 RAC: 0 Level ![]() Scientific publications ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
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I am getting a lot of the "Disk usage limit exceeded" errors now. Was getting a few several days ago but now it is nearly all that error out. It is unclear whether the error message refers to disk capacity or frequency of disk write/reads are exceeded. It would be nice if the project folks would let us know why the error and if there is anything that we can do to reduce the probability of encountering these errors. Basically, there is no point in continuing to run these WU's since nearly all are erring and these SELE6 jobs are thrashing all my machines regardless of number of threads allowed. I finally figured out a way to shrink the linux disk cache from eating all my ram leaving only < 1% free but even leaving at least 4% ram free doesn't stop the thrashing. Maybe if I spring for 32 GB on the 8 core machines with currently 16GB each, the thrashing will be reduced but that won't help the disk errors. Might try on one machine to see out of curiosity. |
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Send message Joined: 28 Jul 12 Posts: 819 Credit: 1,591,285,971 RAC: 0 Level ![]() Scientific publications ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
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I finally figured out a way to shrink the linux disk cache from eating all my ram leaving only < 1% free but even leaving at least 4% ram free doesn't stop the thrashing. Maybe if I spring for 32 GB on the 8 core machines with currently 16GB each, the thrashing will be reduced but that won't help the disk errors. I have a large write cache on all my Ubuntu machines, basically to protect the SSDs from the high write rates of some projects (not QC). But out of 32 GB memory on my Ryzen 1700, I set aside about 8 GB for a write cache, with a 2 hour latency. That allows all the writes to go to the main memory. It also cuts down on the amount written to the SSD, if a given memory location is over-written before the 2 hour latency period has expired. Each time I check it, there are always several GB of memory free or at least available. So, along with about 180 GB free on my SSD, I should not be exceeding any disk limits. But I allow four work units to run at a time maximum (using an app_config.xml); if I cut it down to two at a time, that might work, though I expect that the real problem is something else. |
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Send message Joined: 28 Jul 12 Posts: 819 Credit: 1,591,285,971 RAC: 0 Level ![]() Scientific publications ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
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Please delete. Each time I edit something, it posts a new message. |
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Send message Joined: 26 Feb 14 Posts: 211 Credit: 4,496,324,562 RAC: 0 Level ![]() Scientific publications ![]() ![]() ![]() ![]() ![]() ![]() ![]()
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Yeah, I just stopped accepting new QC work units until they figure out what the problem is.
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Send message Joined: 8 May 18 Posts: 190 Credit: 104,426,808 RAC: 0 Level ![]() Scientific publications
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172,128 QC ready to send, 48 users. No comment. Tullio |
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Send message Joined: 1 Jan 15 Posts: 1171 Credit: 12,662,148,501 RAC: 3,588 Level ![]() Scientific publications ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
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172,128 QC ready to send, 48 users. No comment. this imbalance will not change as long as there is no Windows app for QC. Too bad that it's so difficult come up with one :-( |
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