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Mic

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Message 53697 - Posted: 17 Mar 2012, 2:40:17 UTC

I have an off the wall question. I have an i7-940xm mobile processor overclocked 5%. When I get processes that use the 8 cores I can process 656682 GFLOPS in about 1-2 minutes, but when I am processing the single core versions it takes 3+ hours for only 29640 GFLOPS. Now my question is that when I finish the 656682 GFLOPS I get less than 1 credit most of the time but when I do 29640 GFLOPS I get over 100 credits. That just seems backward to me that when I do more GFLOPS I get less credit since it does not take as long when it uses all 8 of my cores? I hope this makes sence to someone.
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Profile mikey
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Message 53698 - Posted: 17 Mar 2012, 12:00:24 UTC - in response to Message 53697.  

I have an off the wall question. I have an i7-940xm mobile processor overclocked 5%. When I get processes that use the 8 cores I can process 656682 GFLOPS in about 1-2 minutes, but when I am processing the single core versions it takes 3+ hours for only 29640 GFLOPS. Now my question is that when I finish the 656682 GFLOPS I get less than 1 credit most of the time but when I do 29640 GFLOPS I get over 100 credits. That just seems backward to me that when I do more GFLOPS I get less credit since it does not take as long when it uses all 8 of my cores? I hope this makes sence to someone.


Credits are not based on how long it takes, people with slow computers would get tons of credits and the fast pc would get none in that case. Credits are based on how much WORK your pc does during that time.
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swiftmallard
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Message 53700 - Posted: 17 Mar 2012, 12:06:11 UTC

You are crunching both n-body and separation work units. The n-body WUs take just a few seconds or minutes on your system while the separation WUs take 10,000+ seconds. If you want either one or the other, you can set that in your MW preferences.
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ExtraTerrestrial Apes
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Message 53701 - Posted: 17 Mar 2012, 12:59:51 UTC

I don't think these GFLOP number are correct, or at least the amount of credit and computation time you assign are not right. If you look into your profile under "computers belonging to this account" and there on the machine and then "workunits", you'll see that for n-body (all cores) you get about 8 credits per minute, whereas the separation WUs (one core each) take about 10 ks for 160 credits.

Overall that's a maximum of ~10300 RAC for separation tasks and 11000 RAC for n-body tasks. That's a nice agreement, actually. However, AMD GPUs (not your's, only some high end models) can crunch these separation WUs within a minute, so you may consider running only n-body on your CPU to contribute efficiently.

MrS
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Mic

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Message 53703 - Posted: 17 Mar 2012, 17:21:12 UTC

Thanks again everyone for helping me out. I'm sorry if I sound stupid or anything I'm just very new to this and don't understand much about it, but thank you all again for helping me. :)
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ExtraTerrestrial Apes
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Message 53704 - Posted: 17 Mar 2012, 20:31:31 UTC - in response to Message 53703.  

No worries, we're here to help!

MRS
Scanning for our furry friends since Jan 2002
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Terminal123*

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Message 53776 - Posted: 24 Mar 2012, 22:27:56 UTC - in response to Message 53704.  

"However, AMD GPUs (not your's, only some high end models) can crunch these separation WUs within a minute, so you may consider running only n-body on your CPU to contribute efficiently."
I have noticed this as well, however I haven't found a way to ONLY have the GPU do separation tasks and the CPU do only n-body simulation tasks. BOINC keeps downloading separation tasks as well as n-body for the CPU, and separation for the GPU.

Do you know of a way?
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Message boards : Number crunching : Multi core support

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