What are all the differences between the education-only "Late 2011" Aluminum iMac and the regular "Mid-2011" Aluminum iMac models?: EveryMac.com
The Display - The 27-inch Apple iMac Review (2011)
Apple iMac 21.5-inch 2.8GHz Quad-core i7 (Mid 2011) MC812LL/A-BTO | mac of all trades
Apple iMac 27-inch 2011 review | Gadgets 360
Mid-2011 iMac - Upgrading RAM from 4GB to… - Apple Community
Apple iMac 21.5-inch 2.8GHz Quad-core i7 (Mid 2011) MC812LL/A-BTO | mac of all trades
Timetec 8GB Compatible for Apple DDR3L 1600MHz PC3L-12800 for Mac Book Pro (Early/Late 2011,Mid 2012), iMac(Mid 2011,Late 2012,Early/Late 2013,Late 2014,Mid 2015), Mac Mini(Mid 2011,Late 2012) MAC RAM at Amazon.com