Dude don't go for SLI unless you plan to SLI 2 6800Gt's ... if you plan to SLI 6600GT... it's better you buy one 6800 ultra or Gt...look at the SLI board after installing the Card you got hardly any place for normal PCI cards alredi....put one Audigy zs there,..gone...normally a 6600GT's fan will encroach onto the next PCI slot..... don't get SLI unless you plan to SLI the HIGHEST end card... because 2 SLI cards give you lots of Power, but also cost you lots of power and create lots of heat...... In my opinion SLI isn't that good an idea, DFI overclocks better but Abit offers better package.., at lyp i think you can find Fatal1ty for RM630, DFI around RM700,... but if you really want SLI... I think DFI lanparty is the only way to go.