Hi, I recently received an iMac early 2009 model with Intel Core 2 Duo (2.66 GHz), 4 GB RAM and 320 GB HDD. It's currently running Mountain Lion. So far, what I've only done is: - delete the previous user account file, create a new admin account ; - downloaded (but not installed) El Capitan upgrade app. Before installing El Capitan, I'll do a back-up of the "cleaned" system with TimeMachine. The upgrades I'll do for sure are: - Max the RAM to 8GB - Replace the 320HDD to 500 GB SSD. The other hardware upgrade I'm thinking about is replacing the CPU with a Core 2 Duo (3.06 GHz) as they share the same socket. Once the upgrade is completed, then move the El Capitan. My usage (currently I'm doing this on a mid-2012 mbp with i5, 4GB RAM and 500 GB HDD) is: - DxO Optics Pro for raw processing (photography) - iMovie (max 1080p) - GoPro studio & Quik (max 1080p) I'd like to do these task on this iMac which would be way more confortable. Finally my question is: does it worth to upgrade the CPU ?