Right, so from what i can muster up the GPU in my 27" I7 Imac is a Mobility 5850 but under Windows 7 x64 bootcamp it shows as a 5750 and this means that i cant use MSI Afterburner to OC it. I have no idea how to get windows to see my card as a Mobility 5850 not a 5750 and untill i figure out how i cant OC my machine I have tried to install the mobility drivers(i think they are the right ones) but it wont accept the drivers it just says that there are already up to date. Can anyone here help me ? Thanks a bunch. Dane.