Prime95 heals my PC?

[mario1970]

Hi All,
I am new here,and I have a very interesting(annoying) problem.My PC keeps on freezing from the day i purchased it.All parts were tested( Memtest,Hot CPU Tester GoldMemory etc.)but no error.No blue screen,just random freezes while surfing the Web,watching movies.But playing games was no problem,no freeze.
I removed one mem.stick,changed them in different slots,all the same.
Then I was very surprised to find out,that if I run Prime95 while using my PC,it does not freeze.As soon as I stop Prime95,it freezes in a minute.Does anyone have an idea what could be wrong?
Abit AN7
Athlon XP 2800+(no overclocking)
2x512 Samsung 400Mhz RAM
Sapphire 9600XT 128Mb
Pioneer Dvr-109
Samsung 120Gb HDD
PSU: Codegen 300W (maybe this one?)

[Cruelty]

If that was Athlon 64 platform I would bet on Cool&Quiet issues but with AXP it is not the case - maybe look into power management profiles (both in BIOS and Windows)?

[mario1970]

I did that already,all seems fine.Voltage,temperature,all.The thing I do not understand is why it freezes when not under stress.

[Cruelty]

Some things that come to my mind:
Have you installed some custom CPU driver and/or monitoring software? If yes then uninstall it.
Update to the newest BIOS available (if you haven't already).
Where did you get the audio driver from (nVidia or ABIT) - if nV then uninstall it and go for ABIT drivers.
Check the following BIOS settings:
1. Advanced Chipset Features > CPU Disconnect Function = Disabled
2. Integrated peripherals > OnChip PCI device > Audio Controller (disable if you have dedicated soundcard)
3. Power Management Setup > ACPI Suspend Type = S1
4. Power Management Setup > Wakeup by ... = disabled
5. Disable KBPRW1, USBPRW1, USBPRW2 jumpers on motherboard (not exaclty a BIOS setting )
6. PnP/PCI Configurations > Assign IRQ for ... = enabled
7. PnP/PCI Configurations > PCI latency timer - you may look at this setting especially when using SB Live! In such case latency should be increased (max is 255 AFAIK).
8. PC health status > FanEQ Control - disable it
9. Advanced BIOS Features > APIC mode - if you have changed this setting after OS has been installed, then go back to the previous setting (same applies to MPS version), else you should reinstall OS...

Try the above, if that does not help then look for some malicious software running on your PC using MS Antispyware or HijackThis...

[ColdFury]

My old computer behaved like that. When I stopped running a distributed program, my computer would lock up within minutes! It turns out that the processor would quickly lock up when it cooled below about 40 C. I never really determined the reason, but my guess was that there was some loose contact, and when the metal heated up and expanded, the gap was bridged, and then the metal cooled and shortened, the circuit was broken. It made it a pain to reboot the computer because once it cooled down it would not boot. I needed to use a hair dryer to warm it!

[mario1970]

CRUELTY:Thanx,I will try tomorrow,Latest BIOS I have,and right after XP install it might freeze.So I think nothing to do with software or drivers.
COLDFURY:It sounds interesting:what was your solution pls.?New CPU? I do not really mind,just wanna get rid of this annoying problem.

[Citrix]

Tell me which program is using most CPU and memory when Prime95 is not running. Seems like you have a spyware. look into taskmanager.

Citrix

[mario1970]

Thanx Citrix,surely no spyware,because after fresh install without Internet connection it starts to freeze right away.

[ixfd64]

That's another reason to keep Prime95 running!

[mario1970]

Cruelty: I tried everything,but all the same.Thanx anyway.

[lycorn]

Sounds like your PC should post something in the "You might be addicted to GIMPS" thread. Although this is more than an addiction, it is a matter of survival...

But seriously, the heat explanation sounds reasonable to me. The contact between the CPU and socket may be not perfect and the expansion will improve it. Try removing the CPU from the socket and reinstalling it again carefully.
You should also check the voltages to confirm that they do not vary significantly with the system load, and that they are within specs at any time. There may be some issue with the regulator circuit of the motherboard, or with the PSU itself.
Check also the error log of Windows. There may be something helpful in the System error log. See which stop code is referenced there (if any)