Answer to "What GPU's are compatible with iMac 27" 2011?"My iMac (i7, mid2011 gpu with 2Gb) just died this week. I brought it back to my Apple reseller for repair and hè suggested me to provide the original purchase note, because Apple sometimes because of consumer laws decides to repair this without charging costs. I have had many pc's before I got this iMac and never had a dead GPU. PS my iMac was part of the series that could have defective GPU's, but I never traded in my iMac since I had no problems. I agree with some of you that Apple should have proactively recalled those iMacs and replaced the GPU's. Lets see what happens with my repair request..