I forget what year my iMac it but it might be the first 27" i7 they came out withe the aluminum. In any case it has an i7 which is still great, a 2TB hard drive, 8GB RAM, Radeon 4850 512MB. I started experiencing slow performance with beach balls just clicking on a menu or bringing up preferences. I decided to reformat and reinstall and it's still that way. I have annoying times where I just want to click the menu to go to presences or use Finder and I commonly get beach balls and long delays before it does what I wanted it to do. I repaired permissions a few times but it didn't help. Could this performance issue be the hard drive? Is there a good program to test the HD for problems. I don't think an i7 machine should be performing slowly like this. Besides checking the hard drive, should I check anything else? Should I maybe upgrade it to 16GB?