Is Prime95 a good indicator of system stability?

**ahsia** · March 26th, 2002, 08:46 PM

My new P4 rig has ran fine for a week now, but at 2320MHz, Prime95 fails everytime after about 10-11 tests. If I can run Prime95 for hours, does that mean I have fairly stable system? How does Prime95 compare to other Distributed Computing such as SETI, Genome and UD Cancer as far as how much stress it puts on the processor?

**KenKun** · March 26th, 2002, 08:50 PM

They will all take up all the left CPU cycles not in use .. so the CPU will always run at 100% full load ...

It seems that you have a heating problem ... so check your temps ...

Regards

mickwish · March 26th, 2002, 09:07 PM

Yep, kenkun's right, nearly all the DC projects use your whole CPU cycles available, and show up any flaws in your system. If you want to o'clock, I'd say run your CPU / RAM / etc at the speed you can get Prime95 running on for the longest without error. If it won't run at stock speed without error, you have a problem somewhere in the setup. Could be cooling, could be RAM speed, could be vid card conflict, etc.... Troubleshoot time

It's not that hard to cool a P4, is it?

I should have said UD agent works best and then get another cow on the Team! Oh, well, too late now...

**Virus** · March 26th, 2002, 09:53 PM

Prime95 is much harder on a CPU then most DC clients. It has always been a good indicator of CPU stability. If your computer crashes with Prime95. It doesn't mean you will experience crashing when running just your general applications. If you want 100% stability. It is best to run your CPu at a speed that Prime95 doesn't fail at.

**ahsia** · March 26th, 2002, 10:40 PM

Well, I tuned down my FSB, and I am now at 2220MHz, and Prime95 is crunching away, test 640 and counting. I will continue to tweak until Prime95 fails.

By the way, I am fairly new to Prime95. What are some of the errors, and what do they indicate as far as my CPU and clock speeds?

**FalcomPSX** · March 27th, 2002, 12:26 AM

have you tried upping your voltage at all? what's it at?

**ahsia** · March 27th, 2002, 12:32 PM

My CPU is at 1.575, and +.1 on the DRAM voltage. At 2222MHz, Prime95 ran for 10 hours with no errors. I want to keep my voltage steady until Prime95 give errors. I will inch towards 2300MHz. Thanks!

**samwichse** · March 27th, 2002, 01:35 PM

The most common thing I see with Prime95, the first thing to crap out, is that it tends to give "improper rounding" errors. When I overclock, Prime95 is a good canary because it is so sensitive it will give small, non-fatal errors (that don't even close the program) before any real system crashers come up.

It happened on my Athlon classic, my 1.0ghz T-bird, and my stepbrother's 1.2 ghz T-bird that way anyhow.