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Message boards : Number crunching : too many RUNNING tasks

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Ross Dawson
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Message 1304241 - Posted: 9 Nov 2012, 23:21:59 UTC

Hi there.

I have an I7 processor, 8 gig of ram and windows 7 64 bit am running boing xx.28

The problem is I am running 9 tasks one of them being a radeon gpu task (which seem to be all to often ending in error).

In the case of the gpu tasks estimated time is where they start and that figure continually climbs until at some point they error out.

I have completely re-installed boinc (twice now) with the same results.

My stats are dropping like flies on the floor after a spray of raid :)

Any thoughts on this behavious would be muchly appreciated preferably by both a post in here and email/private mail..

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Message 1304247 - Posted: 10 Nov 2012, 0:28:56 UTC - in response to Message 1304241.

You have 4 hyperthreaded cores but probably have your bios set to make it appear to the OS as 8 single-threaded cores.

You could poke around in bios to see if you can change that setting so the OS only sees 4 cores, or you could set BOINC computing preferences to use 50% of the processors.

Some if not most people free up one core for the GPU process to get decent GPU utilization. With your current setup that would mean set BOINC to use 37.5% of the processors. If you change bios so the OS only sees 4 cores you would set BOINC to use 75% of the cores.

Ross Dawson
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Message 1304252 - Posted: 10 Nov 2012, 1:10:12 UTC - in response to Message 1304247.

Well that sort of solved what I perceive to be one of the problems but I don't think it's stopped my ap task errors (which until recently were running propperly and well).

I am now beginning to wonder if the project is sending out crap work units (seems unlikely BUT!)

The ap tasks start out alright counting down in time but then start climbing in time to completion estimate which seems to nearly always be ending in error_time exceeded (or something simillar).

Ross Dawson
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Message 1304268 - Posted: 10 Nov 2012, 3:10:35 UTC - in response to Message 1304252.

Well that sort of solved what I perceive to be one of the problems but I don't think it's stopped my ap task errors (which until recently were running propperly and well).

I am now beginning to wonder if the project is sending out crap work units (seems unlikely BUT!)

The ap tasks start out alright counting down in time but then start climbing in time to completion estimate which seems to nearly always be ending in error_time exceeded (or something simillar).


Further to my previous I have now set max processor usage to 96%.

Getting 7 regular tasks now (with much better looking finish times)
Getting 1 ati gpu plus 0.743 cpu. and have had 2 completed ap work units.

Moral of the story don't set cpu useage to 100% Lets hope it's problem solved.
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Message 1304279 - Posted: 10 Nov 2012, 3:54:31 UTC - in response to Message 1304268.

Multi threading is useful for programs that will not saturate a processor core, so you run 2 light programs on one core. For Seti@home this is not the case. It is written to completly ulitlize a processor core, so you'll want to only have 4 tasks running on a quad core processor. Running 8 will only cause overhead to increase, decreasing actual work.

As for the GPU, you could test to see what it wants from the processor, by clearing your cache, accept only GPU tasks and observe how much cpu is being used by the one GPU task alone. GPU's are generally designed to ONLY handle one task at a time.

On my imac qc i5 i run 4 S@H MB tasks (cpu) and one Einstein@home task on GPU (only uses .5% cpu) so I have no need to throttle S@H

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Message 1304312 - Posted: 10 Nov 2012, 6:06:57 UTC - in response to Message 1304268.

Further to my previous I have now set max processor usage to 96%.

Getting 7 regular tasks now (with much better looking finish times)
Getting 1 ati gpu plus 0.743 cpu. and have had 2 completed ap work units.

Moral of the story don't set cpu useage to 100% Lets hope it's problem solved.


If you are happy with the set up and its running with no errors thats good.

You might consider setting usage to 37%. That will only run 3 cpu jobs at once but they may well run 2x faster than your 7 jobs do now. It's just something to consider.

It will also idle a physical core which many have found greatly accelerates GPU tasks. I have found idling a core speeds them up by a factor of 2 to 3 maybe more. Without doing that I have seen some GPU jobs use 0% of the GPU meaning they don't progress at all.

Ross Dawson
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Message 1304339 - Posted: 10 Nov 2012, 8:18:48 UTC - in response to Message 1304312.

Further to my previous I have now set max processor usage to 96%.

Getting 7 regular tasks now (with much better looking finish times)
Getting 1 ati gpu plus 0.743 cpu. and have had 2 completed ap work units.

Moral of the story don't set cpu useage to 100% Lets hope it's problem solved.


If you are happy with the set up and its running with no errors thats good.

You might consider setting usage to 37%. That will only run 3 cpu jobs at once but they may well run 2x faster than your 7 jobs do now. It's just something to consider.

It will also idle a physical core which many have found greatly accelerates GPU tasks. I have found idling a core speeds them up by a factor of 2 to 3 maybe more. Without doing that I have seen some GPU jobs use 0% of the GPU meaning they don't progress at all.


I think your last observation may have been what was happening here. I will experiment a bit over the next week to see if I can fine-tune things a bit.

Message boards : Number crunching : too many RUNNING tasks

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