I recently began having issues with my late 2012 imac with a 3.4 gHz intel core i7. Performance, delays etc. Ultimately, it was determined my imac was one of those with a faulty 3TB SeaGate hard drive. Like an idiot, I hadn't backed up any of my data. Apple returned me the "faulty" drive and said I could retrieve data from it. Using a SATA to usb along with apple tech support I couldn't even get my imac to recogcize the hard drive. Any suggestions would be greatly appreciated.