Why there isn't NB/CPU clock skew in RF 0410 BIOS? Or it's MoBo function and my P5E X48@RF doesn't have it?

I need to ask something - is VTT tight just with CPU or this voltage have something to do with the NB? I'm asking this, because i have trouble with RAM, i try it at 1130 (it's 1100 by default) and i got errors sec after starting memtest. vNB and vDIMM doesn't help, so, there reason is somewhere else.

If hardlocks are cause by fsb wall, mine is 470. Even 1mhz up and it locks in windows. So far, the only think, that helps are VTT and vNB.