Prime95 and overheating

Hey, this is my first post, i just found out about this form yesterday, and see lots of very helpful people here. I was hoping I could get some help with my new pc..

I just built my first pc about 2 weeks ago, and its a 2.4c P4 with Geil pc3200 512mb ram.. I never installed the intel stock HSF, I just put on the Zalman aluminum model.. I also used AS5.. i've been having a few problems with the pc gettin the blue screen from time to time in the first few days, but for the most part it stopped.

I ran Prime95 last night before i went to bed, I ran 2 instances of it because of the Hyperthreading.. and I did the torture test, I don't know if i was supposed to set it up diffrently in a menu with hyperthreading?

well in the middle of the night my brother wakes me up and tells me my PC is beeping. I run to the pc and i see that the 2 prime 95's are running still and my CPU temp is at 86 degrees C!!

it was probably like that for 3 hours

After reading some posts, maybe i put on the HSF wrong , i do remember when i put on the AS5 i just dabbed a little bit on it, but it was not directly on the center, and just put my zalman on top..

Any suggestions on what it I need to do?

Welcome to the Forum! Please tell us more about your system.
What's your motherboard? Do you overclock your cpu? How do you get your cpu temp?
86C is toooo high if it is true. It's either that your heatsink doesn't sit properly or your bios doesn't report correct temp.

Thanks for the warm welcome.

I have a P4p800 Asus board, and I did overclock my 2.4c to a 2.66 before testing, but i also realized something..

In Prime95 i had the option to put in testing for hyperthreading for each CPU.. last night i was running both prime 95's to run on one processor.. doh!

But this morning i'm testing it again, but now setup correctly to run one Prime95 on CPU 0 and the other on CPU 1.. and i was running it for about 15 min and it never went past 40C.. But i also clocked it back down to its orginal speed 2.4..

I'll try to do longer tests later on hopefully

I get my temps from the moboapp that comes with my asus board and also using mother board monitor, and they give just about the same readings..

I usually idle arond 30C and when playing UT2004 around 38C.. Is that still a little to high if I want to OC? I was thinking more around getting it to 25C idle..

And i heard i need to wait at least a few weeks for the AS5 to really get to its best temp.. what do you think?

You should only use one temp monitoring app at a time - if you use two and get ridiculously high or low temps there is likely a conflict. This is documented for certain programs.

If you had two temp monitors running, that might have been where the temps came from since it sounds like normally you have 40Cish temps.

Thanks IMOG , that was probably the issue.. I'm running prime 95 again the right way with the 2 different prime 95's running on each processor, and it staying around 41C..

but there are times when my pc just freezes out of nowhere, and my screen comes up all messed up an pixelated, i heard there were issues with my 9700pro and my asus p4p800 board, enough so that it actually got mentioned in the mobo manual.. i might still RMA it..

and does anyone have any idea how long AS5 lasts till i have to reapply it?

A long time, as long or longer than any other paste. How long exactly is hard to say, but what I do is monitor temps over time... If I notice an upward trend over the course of a few months, I may consider reapplying.

Usually I'm in their messing around frequently enough that I occasionally reseat the heatsink anyways, so I've never really had to depend on my temp logs. It is still convenient to compare though.

I ran prime 95 last night with my 2.4c at 2.88 and it froze my computer after an hour.. but when i rebooted, i was recording the temperatures, and the temps didn't go past 44 C before it froze, so I am thinking that it could be something else.. possibly my video card? or maybe even my ram or Power supply.. doh...

i have geil pc3200 ram, which is not the top of the line stuff, it has 2.5 cas latency

my true blue 480 watt antec PSU does run a lil too warm for my taste because of that Quiet fan technology, but the voltages seems stable, i've never seen the 5v line go under 4.9, i guess 480 watts is bound to heat up at times


But i am leaning more towards my video card, many times i've rebooted my pc and my screen would come up all checker-boxed and i heard something that when you OC, your agp bus might not be able to keep up.. I am overclocking from my bios with the asus automatic overclock at 20%.. I don't know how to overclock my ram manually yet so i just use the automatic OC, which I hear is not the best if you really want to overclock

I still have only a few more days that I can RMA my 9700pro, i'll probably do it and get a 9800 pro



Any suggestions on what it could be?

look for an option to FIX the AGP/PCI ratio at 66/33mhz

also, check what its at right now, using sandra or any other proggie that can do that

Also, before you go nuts trying to track down the cause of the freezing, set everything to default: cpu, pci/agp, memory timings, etc. Set the memory to SPD. Verify no crashes occur at default settings. Take your time and test it for 24 hrs P95. Once that is established, then start tweaking settings one at a time. If you simultaneously overclock the cpu and put aggressive memory timings, there's no way to tell what's causing any instability issues.

Good luck!

What's the cpu/ram ratio are you running? If you run it at 1:1, at 240FSB your Geil 3200 won't run at that speed. You have to tone it down to 5:4 ratio.

I am not sure what the timings and ratios are set to. I used the automatic overclocking option from my Asus bios.. i overclocked it at %20 to get it to 2.88

But i think the best option would be what timzak said, just run prime95 for 24 hours with everything at default and make sure everything works from there.

linlbij if I got another stick of geil ram and put it in dual page mode, would I be able to put it at that 1:1 ratio?

I'd like to thank everyone for the feedback, its been very helpful and productive

Geil has very little OC room. If you run at 5/4 you need to get to 250 FSB or you will be running your ram slower than 200. The Zalman is a good HSF but not really the best for overclocking however.

infinity9 said:

Geil has very little OC room. If you run at 5/4 you need to get to 250 FSB or you will be running your ram slower than 200. The Zalman is a good HSF but not really the best for overclocking however.

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I dont know about the Zalman not being that good for overclocking I got a Zalman, i can say that it is every good. i got a 2.4b running at 3.2 with my temps being 22C idle and 34C load. Well maybe because i got the all copper one. But Still, its a very nice fan

Some Zalman HSF's do rank fairly high in the rankings, but he is probably right to say that they are not the best heatsinks.

There are also a lot of people who get good overclocks with them, so that isn't to say they aren't for overclocking.

well i've been having a serious issue of my pc just freezing

it happens mostly when i am away from the computer for a long time, and it just freezes when i come back..

i could be away for like an hour and it just freezes..

i put everything back to stock, and gonna test it all out, and see what is causing the freezing.

and my temp when i first got my pc 2 weeks ago was like 29 C with my zalman (the non copper one) just the aluminum, now after trying to OC and after a few rounds of prime95, it has jumped to35 C and that is at idle.. maybe i need to apply more AS5, but it hasn't even been a month yet.. doh..

Actually, the less AS5 you use, the better.