I just got my new mac pro and installed a second 8800GT which works perfectly fine, and also 8GB (2x4) of OWC RAM. When I boot the system it now says 8GB RAM instead of the 10GB I have installed (8GB from OWC and 2GB default Apple). I have them installed as: Riser 1: 2GB | 2GB | 2GB | 2GB Riser 2: empty | empty | 1GB | 1GB The little book that came with the system said if I had 3 pairs to use slots 3&4 which is why I set it up that way. Are there any issues with doing this? Do I have the RAM in the right slots? How can I set this up to see the full 10GB? Thanks!