2011 imac 27" 32GB - final stage of 1TB + 2TB SSD upgrade (replaced HDD & optic drive). Also cleaned out the fans and case. Running 'SSD Fan Control' & 'Macs Fan
HOW TO] iMac 27" (mid 2011) two SSDs in RAID 0 config + HDD | MacRumors Forums
How-To: Now's the right time to swap your old iMac's hard drive for a fast new SSD - 9to5Mac
Installed additional SSD to iMac 27-inch (mid 2011)
iMac 27" Mid 2011 -- fan issues when removing internal HDD? - Ask Different
OWC In-Line Digital Thermal Sensor HDD Upgrade Cable for iMac 2011
SSD Kit for all Apple 27” iMac 2011 Models + tools - 20.17EUR - OWCshop