Hi! I have the 2.8Ghz 8800GS iMac8,1 Theoretically the memory limit is 4GB, at least that's what Apple say, and the Macrumors guide. I've found a few mentions of people having upgraded it to 6GB (one 4GB and one 2GB) though. OWC say it works fine with 6GB. Everything I've seen sofar says it doesnt boot or is unreliable with 8GB, so I'd avoid that unless someone can prove otherwise! I have 4GB in there already, but 6 would probably be handy for Aperture and Photoshop.. Maybe even games once Steam is here.. Does anyone have 6GB in their iMac 8,1? It's a pretty expensive upgrade so I'd need to know it works first.