CPU fan died, prime95 ends after 2min

[a1212]

So a week ago, my cpu fan died, well the cord "fell of" (reason unknown) , put it back in, and it was working again. But windows (and bios) were showing some weird temps, it was very low, 16'C, so I closed my computer and waited about 10min and then started it again, now the temps were acceptable, around 30-40(idling after a couple of min).

The first thing i did was put on Primed95 and a very pitchy noise occured, and after about 2min it ends. But 3dmark03 and 05 are showing regular CPU scores and no crashes. Almost everytime I put prime95 on the same noise comes up. Could it be my CPU fan or my PSU?,. and can the cpu be broken now?.

my comp:

OCZ Modstream 450w
A64 3500+ with Zalman Al-Cu 7000
Neo2 Platinum
MSI 6800GT
one 160gb Barracuda and one 200gb Barracuda
DVD-burner
2*120mm fans
3*80mm fans

 

[evilharp]

Sounds like something was cooked when the fan was disabled.

Run Prime95, and figure out where the "pitchy" noise is coming from (ie. open the case, and listen to the fans).

If you are lucky, it is just the CPU fan, and Prime95 is failing due to a lack of cooling. Replace the fan (if possible) or the cooler+fan, and test again.

If the CPU fan sounds ok, it could be the PSU or northbridge fans. Overheated chipsets/PSUs can cause Prime95 errors.

Based on the temp readings, my guess is it is the CPU fan (your diode was going nuts). You may have cooked the bearings. But I can't say for certain without seeing your kit in person.

 

[a1212]

well I got a new psu (changed my old one), and the sound still occurs. Its a weird sound, I think its coming from the cpu fan, but that doesnt make sense because the cpu fan is plugged straight to the PSU (not via mobo), and it doesnt make that sound while gaming etcetc, only when i put Prime95 on. this is really irritating now, and the NB fan, shouldnt it allways on the same speed??.

 

[Markfw]

I think there is a fan coltroller that runs at high speed when prime is running, since it takes all the cpu. Games quite often don;t use all the cpu.

 

[a1212]

but if the fan is attached straight to the PSU ? how can it then be controlled by some program??

 

[Markfw]

heat controlled ?? I don't know how Zalmanns are setup.

 

[Zap]

Easy way to see if it is the CPU or Northbridge fan. Run Prime95 while the side cover is off the computer. When the noise starts, manually stop the fans in question, as in press down on the center hub of the fan with your finger until the fan stops moving. If the noise goes away you've found your culprit. If not... You can also get a cheap stethescope (perhaps auto parts stores?) to try pinpointing the sound.

 

[Bull Dog]

sounds like electronic noise. Hmm..