the intel mobo cannot do both (sli and crossfire), only crossfire. unless, i guess you hacked the drivers :wink: ..
but i wouldnt reccomend hacking it.... lol
the asus nforce 4 motherboard cannot do crossfire/xfire it only does sli, again unless you hacked the drivers (i again wouldnt reccomend it).
the fact is that no intel chipset (965/975) as of now supports sli, only nforce 4....
however if you want sli i would recomend to wait until the new nforce 5 570/590 motherboards are released, they both support sli *i think* and are supposed to be better than their predecessor(s).
if you need crossfire id be tempted to wait until the new ATI RD600 its supposed to be good and cheaper than intel boards.