Have a mid-2010 21.5" i3 iMac. It came with 2 x 2GB of Ram. I purchased Samsung OEM Ram from OWC 2 x 4GB. My plan was to upgrade the ram to 12GB total. I installed exactly as indicated in the directions. When I fired it up, the fan was running at full speed. The computer works fine and recognizes the 12GB but the fan will not stop. I tried to take the new ram out and just leave the original 2 x 2GB sticks in there and the fan is still going. What have I done? I thought this was going to be such an easy and inexpensive upgrade. Any help is appreciated. Thanks!