32GB (4 x 8GB) PC10600 DDR3 1333MHz SO-DIMMs Memory Compatible with 2011 MacBook Pro, Mid 2010/2011 21.5" & 27" iMac Models, 2011 Mac Mini (OWC1333DDR3S32S) at Amazon.com
32.0GB OWC Memory Upgrade Kit For 2010-2011 Apple iMac
OWC 16GB (2x8GB) ram Upgrade PC3-12800 DDR3L 1600MHz sodimm 204 Pin CL11 Memory Upgrade Kit Compatible with Late iMac, Mac Mini, and MacBook Pro Computer at Amazon.com
install - Installing and Upgrading Ram on a mid 2011 iMac (different size RAM) - Ask Different
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A-Tech 32GB (4x8GB) RAM for Apple iMac (Mid 2010 27 inch 4-Core, Mid 2011 21.5/27 inch) | DDR3 1333MHz PC3-10600 204-Pin SODIMM Memory Upgrade Kit at Amazon.com
hardware - Can I add different size RAMs to iMac 5K? - Ask Different
iMac Mid 2011 (21.5 – inch and 27 – inch) RAM Upgrade Dallas – Apple Mac Computer Repair Dallas , Laptop ,Desktop ,iMac ,MacBook iPhone iPad Data Recovery ,Virus
Memory Upgrades for Apple iMac 2011 Up to 32GB
Install memory in an iMac - Apple Support
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How to upgrade RAM / Memory on a 2010 iMac Core i3 i5 i7 (21.5in & 27in) - YouTube