Setting CPU affinity

[jph1589]

Apparently I've been snoozing on this one. I have thought a number of times that I'd like to experiment with permanantly setting the affinity on certain programs to make them run in one core or the other. The only time I really do it (cause it is a pain in the rear) is when i want to run multiple copies of Superpi. I do that after making overclocking tweaks so that I can fully utilize both cores.

The way I do it for Superpi is a little more involved because you have to have a separate folder for each copy because of the temp files it creates while it is running. So essesntailly I have a Superpi-0 and a Superpi-1 folder with all the files in it. I execute the program from each folder and then go into task manager and change the affinity of each so that zero runs in the zero core and one runs in the one core.

For a while I thought I should be able to automate that but never really looked into it. So I never really did any testing of how it might affect other things that I run simultaneously. In my opinion Windows does a poor job of utilizing multiple core systems but that might be clouded by my feelings that Windows does a poor job of a lot of things. LOL I just hate being a captive to it..... ok I degress.

So if there was a way to do this automatically, I can't imagine why it isn't pretty common knowledge. Hark....there is a way. I haven't tested it yet, because I wanted to hear the moans and growns from others who may have previous experiences. I also don't know exactly how to reverse it should it not give me a warm and fuzzy when I'm all done.

So has anyone ever used imagecfg to permanantly set the cpu affinity for a program?

imagecfg -u c:\path\to\file.exe
imagecfg -a 0x1 c:\path\to\file.exe 0x1 = CPU0 (first logical/physical CPU)
0x2 = CPU1 (second CPU)
0x3 = CPU2 (third CPU)
etc...

I am more concerned than anything about being able to reverse it. So I was hoping to see if anyone had knowledge about that.

[polobunny]

I see little to no use in setting a permanent process affinity to a certain program.
Whenever you feel a slowdown, CTRL+SHIFT+ESC then set the process affinity for programs taking up your CPU ressources. However if you need to "permanently" set a program affinity because of a problem that occurs when you don't, you can either use imagecfg or the more convenient StartAffinity which works great with Windows XP.
All in all, I think you might be expecting too much from dual core. It is a great technology, but it ain't revolution. ;)

[jph1589]

Originally Posted by polobunny

I see little to no use in setting a permanent process affinity to a certain program.
Whenever you feel a slowdown, CTRL+SHIFT+ESC then set the process affinity for programs taking up your CPU ressources. However if you need to "permanently" set a program affinity because of a problem that occurs when you don't, you can either use imagecfg or the more convenient StartAffinity which works great with Windows XP.
All in all, I think you might be expecting too much from dual core. It is a great technology, but it ain't revolution. ;)

Thank you for the advice. This is probably one of those situations when i just have entirely too much time on my hands and like to see how I can tweak things. I will check out Startaffinity though because imagecfg and I have not managed to get along as of yet.

[polobunny]

Oh I would know how it is, I do the same thing all the time. :P