I read somewhere that when selecting torture test to click the "manual" button and change the memory usage to 400.
it depends on your system ram. In my case, I have only 1gb, so I'll manual set each prime95 instance to 400 each, total 800mb out of 1gb.
in your case you could set them to 750mb each, which gives you a total of 1.5gb roughly. I don't remember but I saw it some where that if you ran more than 750mb each instance of prime95, you will get some kind of error.
another different option would be to get Orthos, it automatically runs in dual core mode for you.
To test out your RAM, I'd usually put in 75-80% of your total RAM into it ...
For eg, if you have 1GB, I'd usually put 750-800MB there ...
But then, if you're running dual core, I'd put 375-400MB per instance ...
75-80% along with your applications running, would usually take up 95+% of your RAM, and that's a lot of stress on your RAM ...
With 1 GB Single Core I'd use this:
Typically use <Total System Memory> minus <Video used by onbord graphics if applicable> minus <256 - 384 MB, usually 320 MB for WinXP>
eg: 1,024 - 0 - 320 = 704 MB (+/- 64 MB)
eg: 2,048 - 0 - 320 = 1,728 MB (+/- 64 MB)
If you run two cores, and want to max each one, then divide by two, and use +/-32 MB per instance, so 352 MB between each instance for 1 GB, or 864 MB for each instance of Prime95 if you have 2 GB.
You'll also want Run FTTs in place left off.