Vcore fluctuation

[redhatlinux]

I am not entirely sure that the issue is the actual PS or as pointed out, poor regulation on the mobo. Try unloading devices from your system, and see if you can get any type of stability. Watch out for fans on the 12V line causing electical noise. Maybe you PS has Votage Adjusting Pots that allow for a modest tweak in the 12v, which inturn gives the MOBO a little help. Heat in general will cause 'drift' in any circuit, the drift in this case appears to be focused on the CPU voltage.