Affinity?

mdawson
mdawson
Joined: 23 Feb 05
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Topic 195760

I found a way around the severe latency I am experiencing, but it is not a workable solution. The problem is that with my processor (I7), I have 8 cores. I've reduced workload down to 6 cores, but if I don't manipulate processor affinity, all hell breaks loose. It seems that there is a huge amount of overhead that simply tries to distribute the workload, and it doesn't do a very good job at it.

What I need is something that will force E@H onto 6 of the processors and leave two open for my general use and overhead. From what I've read, there's nothing out there that will do that, or is there?

If I don't do anything, my throughput is abysmal. I was better off on my older quad core with no HT. I don't really want to turn HT off, but without any other solution, I guess that's what I'll have to do. I can't operate like this when lag is 10-15 secs just to get a page to download, or a program to start up, or any kind of window to appear.

ML1
ML1
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Affinity?

Quote:
... can't operate like this when lag is 10-15 secs just to get a page to download, or a program to start up, or any kind of window to appear.

Sounds like you've got some other problem rather than Boinc/e@h... The whole idea behind Boinc is that you shouldn't suffer any slowdowns.

How much RAM does your system have?
What graphics card and how much vram?

Perhaps try a Linux "LiveCD" such as Kubuntu to compare speed?

You can try that without touching your hard drive to see how it runs. Boinc can be installed from the "add software/applications" and is called "boinc-client".

Good luck and happy crunchin',
Martin

See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT [url=http://www.gnu.org/copyleft/gpl.html](GPLv3)[/u

mdawson
mdawson
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Martin, I do use BOINC. I'm

Martin, I do use BOINC. I'm on a Win 7 machine with 12gb ram. I have two video cards, one has 512mb and is single precision GT8600, the other has 768mb of ram and is a GTX 260, double precision capable. I'm only running E@H on my CPU's. I run Collatz on the gpu's.

Yes, I agree something is not right, but I can't figure it out. If I turn BOINC off, this system screams. When it is running and I'm not actively messing with processor affinity, this system crawls.

John Sheridan
John Sheridan
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Have you tried snoozing the

Have you tried snoozing the gpus to see if it gets better? Well optimized GPU tasks make even a gtx580 seem slow.

mikey
mikey
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RE: I found a way around

Quote:

I found a way around the severe latency I am experiencing, but it is not a workable solution. The problem is that with my processor (I7), I have 8 cores. I've reduced workload down to 6 cores, but if I don't manipulate processor affinity, all hell breaks loose. It seems that there is a huge amount of overhead that simply tries to distribute the workload, and it doesn't do a very good job at it.

What I need is something that will force E@H onto 6 of the processors and leave two open for my general use and overhead. From what I've read, there's nothing out there that will do that, or is there?

If I don't do anything, my throughput is abysmal. I was better off on my older quad core with no HT. I don't really want to turn HT off, but without any other solution, I guess that's what I'll have to do. I can't operate like this when lag is 10-15 secs just to get a page to download, or a program to start up, or any kind of window to appear.

Try going into the Boinc Manager down by the clock and then Advanced, Preferences, then the processors tab and down where it says use 100% of the processors change it to 75% and your pc should only use 6 of your 8 cpu's. The problem is that even though you have 8 processors 4 of them are 'virtual', meaning you have a quad core that thru HT thinks it is an 8 core pc. Those 4 HT cores require the first 4 'real' cores to do their work, slowing your pc down in some ways and speeding it up in other ways.

MarkJ
MarkJ
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RE: What I need is

Quote:
What I need is something that will force E@H onto 6 of the processors and leave two open for my general use and overhead. From what I've read, there's nothing out there that will do that, or is there?

Yes there is. Just set the % of processor use to 75% in BOINC and it will use 6 cores and leave the remainder free (well the GPU jobs will be able to use them but they shouldn't use much CPU time).

Under the 6.12 client the option is under Tools -> Computing prefs -> Processor usage tab. Under older versions I think it was under Options -> Computing prefs -> Processor usage tab. Or you can set it via the website.

You'd probably want to run Task manager and see whats taking all the cpu or disk I/O time. Click on the Process tab and sort on the CPU column descending and see whats using it all.

Jord
Joined: 26 Jan 05
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RE: Under older versions I

Quote:
Under older versions I think it was under Options -> Computing prefs -> Processor usage tab.


Nah, it was under "BOINC Manager->Advanced view->Advanced->Preferences". :)

dunx
dunx
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I see a 60% icrease in

I see a 60% icrease in throughput using HT to process 8 threads...

I also run @ 75% to leave 2 threads free for surfing the web, and to feed my 2 x GTX460's.

dunx

mdawson
mdawson
Joined: 23 Feb 05
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OK, I'm a bit confused now. I

OK, I'm a bit confused now. I have the option for "on multi-processors, use at most x cpu's" set to 6, and the option for "on multi-processors, use at most x% of the processors" set to 75%. These both read the same to me, but there must be a difference in functionality.

So right now, I'm crunching on 6 cores and it's the various Einstein apps that are using up the vast bulk of resources.

Gundolf Jahn
Gundolf Jahn
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RE: OK, I'm a bit confused

Quote:
OK, I'm a bit confused now. I have the option for "on multi-processors, use at most x cpu's" set to 6, and the option for "on multi-processors, use at most x% of the processors" set to 75%. These both read the same to me, but there must be a difference in functionality.


It's not a difference in functionality, just in BOINC versions.

The first one is for BOINC versions before 6.1 and the latter for versions 6.1 and up (as you can conclude from the addendum "Enforced by version 6.1+" in the computing preferences;-).

Gruß,
Gundolf

Computer sind nicht alles im Leben. (Kleiner Scherz)

dunx
dunx
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In BOINC 6.12.15... Use

In BOINC 6.12.15...

Use 75% of the processors should use 6 threads for CPU work units.

Use at most 100% leaves room for thermal management... When the ambient is very high here in the U.K. I set this to 80% as I run both quick PC's @ 4 GHz..
This sets BOINC to leave 20% of the CPU cycles as idle, thus the system runs cooler.

My problem is with Aqua's FP WU as they run the CPU @ 100 % for a considerable length of time.

HTH

dunx

P.S. Update the project or tell BOINC to read local prefs. once set.

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