A dual cpu mobo, 2 amd opteron's 246, mobo can hold 8gig ram for each cpu, total 16gig. Had 1 gig stick for each cpu (2gigs total), added 2 more 1 gig sticks (4 gigs total) So now it has 2gigs for each cpu, windows only see 3.68. Is this a limitation of winxp pro 32bit? Will win64bit solve this? What if i wanted 4gig for each cpu?