Hmz only way to be sure is to hook up a voltage meter, or someone else has to have done it before you, and reported back on it, how reliable is 1 single test though ? Also, I think it's vdrop, but don't take my word for it. I think it has something to do with the core getting less vcore, because when your system comes under heavy load, other hardware will need more power as well, and then your power supply can't hack it resulting in 'vdrop', which could then result in system instability ... Better have some longtime poster confirm this though ...
Oh, vdroop also exists, and is basicaly the same thing, the vcore on your cpu being lowered, but it happens due to motherboard specifications, seems to be a protection of some sort.