my Linux pc is randomly powering off. the working configuration:
- ATI drivers (fglrx) not loaded
- cpufreq governor (either performance or powersave) and frequency are set at boot (default settings compiled into kernel).
- no suspend-to-RAM (pm-suspend) happened.
Switching cpufreq governor to 'performance' leads to shutoff in ~hour. CPU temperature is normal all the way.
There is a small chance of PSU bugs, but the performance configuration doesn't tends to shutdown often. It seems that a motherboard GA-890GPA-UD3H has a bug in ACPI/somewhere else (wrong AMD Turbo switch?), that is triggered by some PM/cpufreq call to evolve, live and block the whole system unless the AC cable is cut for 5 seconds. It also may be due to PSU, however.