Hello, your power supply is hardly ever giving exactly the power it should. But it's usually still within a certain percentage and the power dropping to below 3V is probably over the borderline.
Check the recommendations given by your motherboard manufacturer on the kind of power it needs. You've got rather a large amount of power required to run all that stuff!
So the PSU is the first place I'd look.
As far as the temperature goes, maybe the core temperature of your new board has something to do with the increase on your CPU.
Regards
Martin
