This meant upgrading the RAM (very easy) and upgrading the CPU (more challenging). Since I was going to be opening up the iMac14,2 I figured I might as well perform any other upgrades that could squeeze some more speed and life out of the computer. I resisted as long as I could, but eventually I saw no way around cutting open the iMac14,2 and installing an NVMe blade SSD. Even the iMac15,1 only has thunderbolt 2 support. Four-bay thunderbolt enclosures are expensive and the iMac14,2 only has thunderbolt 1 support. My first thought was that a thunderbolt-connected external drive enclosure with 4 SSDs in RAID 0 for speed or RAID 5 for speed an safety would help. It seemed to take far too long to login and to start applications compared to my Late 2014 Retina 5K iMac15,1 with a 512GB SSD (more on that later). I felt like the performance bottleneck in my Late 2013 iMac14,2 was the 1TB spinning mechanical hard disk. The 27-inch iMac has a RAM hatch on the back which an end user can open to install up to 32GB of RAM (or more in more recent iMacs).

Officially not much can be upgraded internally. Emboldened by my success upgrading my 5th generation iPod and frustrated by the slowness of one of my iMac’s I decided to see what end user upgrades are available for post-2012 iMacs.

Imac 27 late 2013 os upgrade