I recently bought myself a brand new Samsung 750GB SATA hard drive to put in my ‘Late 2006′ 20″ iMac. The machine is a 2.33GHz Core 2 Duo with 2GB RAM and a Radeon X1600 Pro 256MB. So I followed the steps to open it up and removed the screen, then replaced the drive and reassembled.

Next I booted up and everything seemed to be fine, started installing Leopard and noticed it was taking a while to install, 5 hours to be precise! I then put my old hard drive in a FireWire Caddy and used Apple’s ‘transfer data from another Mac’ option to get all my files back, this took about 16 hours!

After all was done I started using Leopard for a while only to find that every minute or so the system would beachball and become unusable for about 2-3 minutes. It would then catch up with itself and a minute or so later, beachball again! I trawled the internet for answers and found someone else on the Apple Support forums that had bought the same hard drive and had exactly the same issues. He told he’d returned his Samsung drive and bought a Seagate model, which he said worked fine.

Two days later I have my new Seagate 750GB hard drive waiting to be fitted. I go through all the motions again, removing the iMac’s front, taking out the screen, installing the hard drive. Guess what, it also had the beachball problem! I even tried using a jumper setting to force SATA 1.5Gb/s mode, still the same!

So now I’m back with my original Seagate 250GB hard drive installed, and am booting the iMac from the Samsung drive using my FireWire Caddy! No beachballs at all now! I can only think that the SATA Controller in the iMac just can’t cope with a drive bigger than 500GB. Time for an Aluminum iMac I think…