How do you get two instances of Prime95 to run?

[Goronmon]

Seems like everytime I try to do it, it doesn't work, Prime95 just sits there doing nothing and the temps are hardly above idle...

 

[L337 M33P]

Run an instance of Prime95. Then go to Start-->Run and type the location of Prime95.exe with the switch -A1 after it. This will bring up another instance that you can set to the 2nd virtual CPU. (CPUID 1)

 

[Goronmon]

That doesn't seem to work...they don't seem to actually get any work done and the temps are barely above idle...

Edit: I wonder if its running version 23.8 tht isn't working...

 

[stui_nz]

maybe try these instructions - (worked for me)

Install the program, then go into the Program Files folder, copy the Prime95 folder to your desktop, rename the new folder Prime95-2. Rename the executable Prime95.exe to Prime95-2.exe. Now place that folder back into Program Files and make shortcuts to Prime95 and Prime95-2 on your desktop. Now, when you open both, you can tell the difference between the two, when you open Task Manager.

You can run two instances normally, or you can assign each program it's own affinity (CPU.) I'm not sure if the latter has any advantages, but it might help you determine if one of the CPU's is less stable than the other. If Prime95 fails (usually happens in the first 10 minutes) the usual fix is to raise Vcore or lower the CPU speed. For an absolutely stable system, run these two instances of Prime95 overnight. If they are still up and running in the morning, then you are rock-solid.

By the way, turn off any folding@home or anything like that, while you are running the tests, otherwise the folding@home takes CPU cycles away from Prime95 and Prime95 takes longer. (which doesn't really matter, except it might take longer for an error to show up, if it encounters errors.)

*EDIT* Make sure each copy of Prime95 is only using about 25% of your total system memory. By default, it will want to use 75% of your system memory. This is no good, when you're trying to run two instances, because it will need 150% of your RAM to run the tests. Because that RAM isn't there, it will use the paging file, instead and it will take forever to do anything. Go to Options, then click on CPU, then change the daytime and nighttime memory available to 25% of your total memory.

 

[Goronmon]

Its just not working, as soon as I try to run two, its like they cancel each other out and nothing happens...

 

[racpuc]

just have prime located in different directory and use different versions. Thats how I run two prime programs at the same time

 

[NookieN]

If you're trying to run a torture test with both instances, you will probably need to reduce the amount of memory that Prime can use. If you tell each instance to use 90% of the RAM in your system, they can stall. Instead, set each to use only about 40% of your memory.

 

[zabomb4163]

in task manager change the cpu affinitiy. or in prime options.

 

[Goronmon]

Alright, looks like the problem is that no matter what the memory usage settings are at, Prime95 always takes up all the available memory on my system (ie. I have it set for 128MB and its using 905MB)...anyone have any idea on how to fix this?

 

[NookieN]

Are you setting the memory available to Prime in the "custom" section of the torture test menu? The memory section of the CPU menu only affects factoring and LL testing, not the torture test.

 

[Goronmon]

Ah...I did not know that, thanks for the help

Edit: In that case, what should I use for settings?

 

[NookieN]

The settings for testing are up to you. The general-purpose Blend test uses FFTs from 8k to 4096k. For memory, if you're running two instances give each about 40% of your RAM (so with 1GB, each should get about 400-420M). You shouldn't need to use more than that.

 

[Goronmon]

Well, I'm running one instance of the Large In-Place FFTs (the second option) and one instance of Custom with 900MB available...seems to be pushing the whole system pretty good...

Thanks for the help