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Former Member
Cruncher Joined: May 22, 2018 Post Count: 0 Status: Offline |
I have two "work units" being processed simultaneously and this would seem to be counterproductive to having all processor power working on only one unit. Is it normal to have two downloaded and being processed at a time?
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Former Member
Cruncher Joined: May 22, 2018 Post Count: 0 Status: Offline |
I have two "work units" being processed simultaneously and this would seem to be counterproductive to having all processor power working on only one unit. Is it normal to have two downloaded and being processed at a time? Perfectly normal (and very productive) if you have a dual-core processor? |
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jal2
Senior Cruncher USA Joined: Apr 28, 2007 Post Count: 422 Status: Offline Project Badges: ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
However, it can be counter-productive if you are using simulated (hyper-threaded) processors. Ideally, the number of WU should not exceed the number of physical cores.
----------------------------------------There are discussions elsewhere about multi-threading the WUs across multiple physical cores. ---------------------------------------- [Edit 1 times, last edit by jal2 at Oct 25, 2007 7:54:42 PM] |
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Former Member
Cruncher Joined: May 22, 2018 Post Count: 0 Status: Offline |
Thanks for the quick responses. Obviously I am new to this.
![]() Yes, I am using a dual-core PC. |
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Former Member
Cruncher Joined: May 22, 2018 Post Count: 0 Status: Offline |
However, it can be counter-productive if you are using simulated (hyper-threaded) processors. Ideally, the number of WU should not exceed the number of physical cores. There are discussions elsewhere about multi-threading the WUs across multiple physical cores. Can you elaborate? I'm running on a hyperthreaded pentium IV single-core processor and I'd like it if I could just do 1 at a time instead of 2. |
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Former Member
Cruncher Joined: May 22, 2018 Post Count: 0 Status: Offline |
Hello Blarrrg,
Good idea! The Pentium 4 will run 2 threads simultaneously unless you specify only 1 thread. 2 work units take twice as much memory but run only slightly faster than a single thread. Go to My Grid - Device Manager and click on your device profile. This will bring up the device preferences page. By default, it is set to run up to 4 threads per processor. Set it to run only 1 thread per processor, then SAVE the new profile. After your BOINC client downloads the new profile, it will only run one work unit at a time. This is better than 2 unless you have lots of RAM and do not use your computer much. Lawrence |
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crooks_uk
Veteran Cruncher England Joined: Nov 25, 2004 Post Count: 1011 Status: Offline Project Badges: ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
Hello Blarrrg, Good idea! The Pentium 4 will run 2 threads simultaneously unless you specify only 1 thread. 2 work units take twice as much memory but run only slightly faster than a single thread. Go to My Grid - Device Manager and click on your device profile. This will bring up the device preferences page. By default, it is set to run up to 4 threads per processor. Set it to run only 1 thread per processor, then SAVE the new profile. After your BOINC client downloads the new profile, it will only run one work unit at a time. This is better than 2 unless you have lots of RAM and do not use your computer much. Lawrence I know that this has been discussed in detail in the past. But, I have ran all versions on the BIONC agent on 3 x P4 HT machines, running two units at a time, with all machines having 512MB RAM (not a lot these days) and have never had any problems.
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Sekerob
Ace Cruncher Joined: Jul 24, 2005 Post Count: 20043 Status: Offline |
One process runs in the real core. The other is virtual and uses the small gaps. The process manager will show each using 50% i suppose, but in reality the 2 processes are getting half and a few percentage points more from the little gaps that HT is utilizing, so in the end your 2 jobs finish in near twice the wall-clock time versus. Depending on RAM it could even take longer than twice on the wallclock because of e.g. swapping.
----------------------------------------Whilst it may work for the individual case, the recommendation is to just allow 1 CPU in the profile *for HT* CPU's. If you try, you will discover that a job finishes in half the wallclock time. Added Rumour has it that Intel is going to re-introduce HT in their dual cores.... they dropped it apparently due design complications building the original duo's.
WCG
----------------------------------------Please help to make the Forums an enjoyable experience for All! [Edit 1 times, last edit by Sekerob at Nov 20, 2007 12:43:31 PM] |
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