Like the title says, I have an Early 2009 Mac Pro w/8x 2.26 Xeon cores. I want to upgrade the RAM to 12GBs (it currently has the stock 6GBs (6x 1GB)). If I remember correctly, it is better to add these in sets of 3. So if I get a Crucial 12GB kit (3x 4GB), do I split them up, or put all 3 on the same quad processor (essentially giving me 15GBs if I leave both slot 4s empty)? I would love to replace all 6 with 4GB chips but that isn't in the cards right now. So any advice would be helpful.