Originally Posted by raxen
Like any good science experiment, change only one variable at a time. Here's how I would proceed:
1. Stability test system at stock settings.
2. Test system with cores unlocked at stock frequencies.
3. Test system with multiplier increased. Increase multiplier by half step, test, and increase voltage by one step if fails. Rinse and repeat. I know this is tedious.
4. Test system with cpu-nb multiplier increased (Depending on your chip, it may not overclock well. Remember they are dual-cores for a reason. Either the core was defective, or the cache was. In your case, very well may have been cache defective.
5. Test system with CPU AND CPU-NB multiplier increased.
That Vdroop isn't looking very good. Then again, you can't rely on software. 100% sure check is with a multimeter.
Thanks for the reply but trust me, I've done the grunt work. Here's the gist of my log:
Unlocked successfully to X4 B50
3.1Ghz @ Auto voltage: success - prime small fft 9.5 hours (no errors)
3.2Ghz @ Auto voltage: success - no stability test, continued to push higher
3.3Ghz @ Auto voltage: success - prime blend 11 hours (no errors)
3.4Ghz @ Auto voltage: failed - prime blend 2 hours (BSOD)
3.4Ghz @ 1.35V and 1.375V(CPU): failed - prime blend 2 hours (BSOD)
3.4Ghz @ 1.375V(CPU) & 1.25V(CPU/NB): failed - prime blend 1 hour (BSOD)
3.4Ghz(CPU0,1) & 3.3Ghz(CPU2,3) @ Auto voltage: success - prime blend 14 hours (no errors). Load temp: 48C
Even at 1.375V, I'm getting a pretty large Vdroop with CPU-Z reading 1.312V during prime blend and fluctuations in the range of 1.296-1.360V. This might be the reason for instability. Is this my motherboard's fault or PSU?
I'm thinking about enabling 'LoadLine Calibration' to minimize vdroop since I'm not up in the 1.4-1.5V range but I'm still not sure if that's a wise thing to do. Not sure what it does on Auto. After that, perhaps I'll try 1.4V(CPU) and then 1.3V(CPU/NB) as suggested.
Good plan or am I missing something? Would I be better off reverting back to dual core and going for ~3.6Ghz?Edited by Bkobe7 - 12/1/09 at 4:30pm