CPU Stress programs not working.

ben16 · 15 Sep 2007 at 20:50

I'm trying to stability test my CPU using stress tests but they're not working.

With prime95 (latest version) the CPU load just hovers around 30% on the torture test and if I run Orthos (again latest version) it only stresses two CPU's ( but to 100%)

What am I doing wrong?

DavidB · 15 Sep 2007 at 20:55

think you have to open 4 instances of prime, 2 of orthos might work i suppose..but i havn't seen it done.

ben16 · 15 Sep 2007 at 21:05

Thanks but when I open two instances of Orthos it just tries to stress the same cores, it's like it can't see the other two.

Opening up multiple primes doesn't help. It's not even stressing two cores fully.

mk17 · 15 Sep 2007 at 22:38

download prime 95 v25.4 - this allows the user to set the number of simultaneous tests to execute. set this to the number of cores you have and execute. Dunno about orthos.

ben16 · 15 Sep 2007 at 23:21

mk17 said:
download prime 95 v25.4 - this allows the user to set the number of simultaneous tests to execute. set this to the number of cores you have and execute. Dunno about orthos.

Thanks. I did that and now it it says all cores are being stressed. All say 100% in task manager but cores 2 & 3 are running 10C cooler than 1 & 2 according to Core Temp. :confused:

Cob · 16 Sep 2007 at 00:28

ben16 said:
Thanks. I did that and now it it says all cores are being stressed. All say 100% in task manager but cores 2 & 3 are running 10C cooler than 1 & 2 according to Core Temp.

That would suggest that either your heatsink isn't fitted correctly, or your heatsinks base or your CPU aren't exactly flat.

ben16 · 16 Sep 2007 at 00:59

Before overclocking load temps look like this:

Is it worth fiddling with the heatsink or are they ok?

Cob · 16 Sep 2007 at 01:06

That's pretty nasty. Re-seat the heatsink (which cooler is it?).

But while you're doing it, take a look at the imprint of the old paste on the heatsinks base to see if it has made good contact. Also remove the CPU and check its flatness by holding the edge of a credit card or similar on it and seeing whether there's a gap. Do the same with the heatsinks base too.

ben16 · 16 Sep 2007 at 01:11

It's a Thermalright Ultra-120 Extreme cooler. How should I remove the thermal paste from the CPU and heatsink?

How tight should the heatsink screws be onto the mobo? I felt I could have tightened them a bit more but I didn't want to risk going too far.

Cob · 16 Sep 2007 at 01:17

Have you got any spare paste? If not, then don't remove it until you get some.

Paste can be wiped off with a tissue and then cleaned with some alcohol or similar.

You should probably tighten the screws by hand until you feel some real pressure. And always do one corner, then the diagonally opposite corner eg- top right, bottom left, top left, bottom right.

But the Ultra120 has been known to have an uneven base, and sometimes needs to be lapped (sanded) down a little to make it flat. But then again the Intel chips are often less than perfect. I had to lap my Q6600 as there was an 11c difference between the cores. Lapping brought the difference down to about 4c under Prime load.