Chosen Solution
Mid 2011 27” IMac, I5, 2.7GHz, MC813LL/A, A1312, EMC 2429, GPU AMD Radeon HD6770M 512Mb. I found a HD6770M w/1Tb…will this work or just cause another headache & put good money after bad?
Apple offered three dedicated GPU options in this series: AMD HD 6770 w/512 MB - Apple P/N 661-5967AMD HD 6970 w/1 GB - Apple P/N 661-5968AMD HD 6970 w/2 GB - Apple P/N 661-5969 You need the Apple versions as they have custom firmware. Otherwise you can use any one of these. As to how you killed the GPU that can be a bit tricky! First people expect more from this system than what it was designed to run. Keep in mind this system was designed late in 2009/early 2010 consider what apps where being run back then. Today we have games that really push the limits of even the newest systems and some Pro apps likewise do some fantastic stuff but push the system to the edge. So, the first thing are you running the system too hard? I would recommend installing a good thermal monitoring app like TG Pro The next task is keeping the system as dust free as you can as the build up will prevent the proper cooling of the system. In addition you should clean off the old thermal paste on both the CPU and GPU as well as the Video RAM chips. Besides applying fresh thermal paste on the CPU & GPU You’ll also need to replace the thermal pads on the RAM chips with fresh pads. Personally I love the 2011 27” iMac I have one and I’ve managed to keep it running. But, I too killed one GPU board doing some heavy photo editing. I went with the 2 GB board and it held up quite well. I’ve since jumped to a 2013 Mac Pro for my photo editing. I still use the iMac for lighter tasks.
