yes, the 8IEXP has a 1:1, 3:4, and 4:3 mem ratio.
However, I strongly urge you to reconsider buying this board. On paper it does look like the best 845E board out there, but it's not. I fell into the trap about 2 weeks ago and had to RMA mine back to newegg because it was *not* stable. I took a 1.8 that I've had at 2.52 and put it in and i couldn't even post at 2.4.
Do not buy this board. I ended up with the IT7 max and I absolutely love it. Another great board is the p4B533-E, but it's $20 more. Ask around, you'll see a lot of other people having bad experiences with the 8iEXP board.