Sorry for the double post but I as it turns out I am stumped...

Whats the trick to get 4gb of ram to overclock as well as 2gb?
I can run any 2 sticks fine at 1800 (8-7-6-12 1t) and vDimm = 1.90 (1.96 real) but when I run 4 sticks it wont pass memtest at anything higher than 1700 (8-8-8-20 2t).

Is it something in my vdimm ref settings on the channel basis?
Perhaps I need more vFSB when I am running more ram...

Any of you guys running 4gbs at high overclocks and 1t without any issues if so can you point me in the right direction?