Hyperthreaded scheduling between projects

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Adrien Seldon
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Message 102115 - Posted: 21 Apr 2005, 6:02:37 UTC

I have a hyperthreaded processor and I am wondering if there is any way to make one of the "logical" processors always run seti while the other switches between the other projects I am participating in.
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Profile Saenger
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Message 102116 - Posted: 21 Apr 2005, 6:06:27 UTC

Hello Adrien,

AFAIK no, but if you leave the SETI share to 100, and set all the others to values that add up to 100, the effect will be the same. Boinc is designed for optimal use of your CPU(s), and will do so on it's own.

Or are there any special personal preferences for one of your virtual CPUs ;)
Gruesse vom Saenger

For questions about Boinc look in the BOINC-Wiki
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Profile Geek@Play
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Message 102117 - Posted: 21 Apr 2005, 6:11:45 UTC

AFAIK = Always Fear Aliens in Kansas???
Boinc....Boinc....Boinc....Boinc....
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Message 102121 - Posted: 21 Apr 2005, 6:32:47 UTC - in response to Message 102117.  

As far as I know.
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Message 102156 - Posted: 21 Apr 2005, 10:58:11 UTC
Last modified: 21 Apr 2005, 10:58:34 UTC

Unfortunately, HT processors are no different than regular singular pipeline ones when it comes to processing percentages. It simply treats it as two cpus, and when you say 100 % seti, an 50 another, and 25 anothe it will simplyadd all up, divide into a real 100%, and th slit across one thread the %'s ad thesame %'s across the other. There is no way to dedicate a CPU. I see it round robining through mine. At first it seems like the two threads are following one another, but then after a while, due to some usage of the computer to read mail, or to play a quick game of alchemy, or to compile a VC++ routine, etc., they get out of sync, but the percentages hold to the round robin and to the time you say to switch betweenprojects. If you say 100 and 50 and 50, then it will go to the a process, then to the b, then back to the a, then to the c, then back to the a, etc. It seems % really only dictates when you tell it how often to switch, who will get switched to. I may be wrong on that one, but overall, that is what I have seen on mine.
Only way to get one to get more processing, is to up its percentage in relation tot he others. Doesn't matter if you give it 10000 and the others 5, just means it will switch back to the first one more often, even switching back to itself. I have seen that on mine, where it says in one line
pausing seti #1
then immediately afterwards
resuming seti #1,
meaning it prioritized itself back to the one it paused.
Kind of inefficient, but it doesn't matter, what are a few wasted clock cycles when consuming billions of unused ones.

Hope this helps, as this is how I have seen it operate on mine.

Keep on Crunchin,
John Henry
Sevierville, TN
Thanks, and Keep on crunchin'
John Henry KI4JPL
Sevierville TN

I started with nothing,
and I still have some of it left.
<img src="http://www.boincstats.com/stats/banner.php?cpid=989478996ebd8eadba8f0809051cdde2">
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Profile Paul D. Buck
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Message 102211 - Posted: 21 Apr 2005, 16:37:21 UTC - in response to Message 102115.  

> I have a hyperthreaded processor and I am wondering if there is any way to
> make one of the "logical" processors always run seti while the other switches
> between the other projects I am participating in.

If you have a total of 5 projects ...

Resource Share
SETI@Home 400
Project #2 100
Project #3 100
Project #4 100
Project #5 100

Will make SETI@Home run more than the other projects with half the time for SETI@Home and the remainder for all of the other projects. Look in the glossary for resource share for other examples ...
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Message boards : Number crunching : Hyperthreaded scheduling between projects


 
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