Review on 💾 16GB A-Tech RAM Upgrade Kit for Apple MacBook Pro (Early/Late 2011), iMac (Mid 2010 27 inch 4-Core, Mid 2011 21.5/27 inch), Mac Mini (Mid 2011) - DDR3 1333MHz PC3-10600 204-Pin SODIMM Memory by Robert Mulrooney

Apple memory specifications for Mid 2011 iMacs: 16 GIGABYTE max. The web description says it will be operational by mid-2011. After installing the memory, iMac shows 32G and iMac works fine for a while. It quits and restarts unexpectedly, and the error message indicates a memory problem. I ran the Apple Hardware Test and the memory failed the test. I received two replacement memory cards and swapped out the existing cards hoping to find the defective card. Problem still exists. I reinstalled the original 16G chips and there were no more errors. Although the iMac recognizes the storage, it will not function properly if you exceed 16GB.