It froze like a minute after stopping prime95 small FFT that I ran for 5 minutes. Maybe increasing offset voltage is not the solution to this problem. I'm not going to increase it further since it doesn't seem to be helping. What other BIOS settings should I try?
This is at +0.070V in BIOS for CPU offset voltage. CPU-Z says the voltage at idle is 0.900V, though occasionally it drops to 0.888V for a few seconds when going from high cpu usage down to idle. When running p95 v26.6 small FFT it says the voltage is 1.092V, however occasionally it will show 1.200V for a second or two (not on p95, but when something else uses lots of CPU usage temporarily). OpenHardwareMonitor said CPU package temperature was hovering around 69-71C (room temp is 27C) after 5 minutes of p95 small FFT, at idle it was hovering around 37-43C.
Everything in BIOS is set to Auto, except for CPU Offset Voltage which I set at +0.070V. Is there anything else in BIOS I should try to set to stop it crashing when it goes from under load to idle / light load? I want to undervolt my CPU as much as I can if it hasn't actually degraded, my goal is stability (obviously), lowest temperatures without underclocking from stock and I want to keep SpeedStep enabled since the PC is much more often idle / light load than under load. In AI Tweaker DIGI+ VRM section of the BIOS, LLC is set to "Auto", it has 5 other options "Regular", "Medium", "High", "Ultra High", and "Extreme". There are 4 other VRM settings "Fixed Frequency", "Power Phase Control", "Power Duty Control", "Current Capability". I should also mention the PC can boot at lower voltages like -0.080V offset, but it freezes more often in Windows or Kubuntu (live session USB with HDDs unplugged) like after 2 hours.
Mobo: ASUS P8H61-M LE/CSM R2.0 (with latest BIOS 1414)
RAM: 2x8GB DDR3-1333 (tested 1 pass memtest and 30 mins p95 blend test, no errors)
PSU: CX430 (also tried a different PSU, still had freezing)