stolen in full from there
Prime95 Word of Advice
Based upon the number of PMs I have gotten in the past fews days about a rant of mine here , I thought I'd pass it along again, but not buried in someone elses thread.
If you use Prime 95, either the current release or the current beta, to establish an OC stability, you can't just download it and run Torture Test at the default settings.
There is a parameter called Priority, accessed from the Advanced tool button. By default it is set to 1 of 10. At Priority 1, it will exercise your setup, but not stress it anywhere near its capacity. Kind of like pumping weights for 10 seconds, resting 90 seconds and repeating...
You need to set the Priority to 10. At a Priority of 10, Prime 95 Torture will really "put the spurs" to your setup. With it running at that Priority, you won't be able to do much else with your PC. It consumes so much of your system resources, even trying to stop it, using the tool buttons Test / Stop takes a few seconds. MBM, which I like to run while stressing will be slow to update, even set for as fast an update as possible, but it will eventually update its readings.
"Oh, but my Priority button is grayed out!" you say. That's because you probably didn't RTFM. In order to access the features in the Advanced section, Prime95 requires you to enter a Password. It's the same Password for every version I have used.
"Oh, but I don't know the Password!". Again, that's probably because you didn't read the readme.txt file that came with Prime95, aka RTFM. It is in the readme file, but to save the incredibly lazy the time, it is 9876.
In the Advanced section, set the Password to 9876 and then set Priority to 10. Leave the rest alone for the sake of everyone "singing from the same page".
Prime95 will remember your settings, so no need to enter them every time you use it. Now you're ready to really test your systems stability. Click on the Options tool button and Torture Test.
A note for those of you using the current Beta version. When you click on Options / Torture, you will be faced with a dialog box requiring you to make one more choice. Check the box with the test that goes something like: Use Large, In-place FFTs...
I think it is the middle choice of three check-boxes. That will stress your setup the most. That choice will not be remembered the next time you run Prime95, rather it requires you to make that selection every time you run Torture test.
One last word of advice. Don't run other stressing, stability, or synthetic benchmark tests in parallel with Prime95 Torture Priority 10. You don't get extra credit for that accomplishment and you are better off leaving Prime95 alone to exact as much punishment upon your setup as possible, without interruption.
Now, go forth and see just how stable your setup really is. I apologize to those veterans who already knew this and read through this lengthy monologue in hopes of gleaning some "earth-shattering" morsel of knowledge.
For dual-core stress testing use SP2004 Orthos Edition: http://sp2004.fre3.com/beta/beta2.htm
For quad-core stress testing use the multithreaded version of Prime95: http://mersenne.org/gimps/P95V253.ZIP