Answer to "M.2 SSD Installation iMac 27 "5K Retina"I replaced my stick and its not a change at all I get the 1 Terabyte but the speed is about the same just volume gain thats ok. I never had a fusion drive so I did get to put in a 500 G where there was none, thats a gain to and faster than external by just a bit. The NVME is better off on the outside if you have a fusion drive inside its a easy change up. If there is going to be a Firmware update to stop the bottlenecking on the 15,1 27” iMac then we will see a gain. Personally I thought the process of putting in a new SSD was very easy I had to add the cable and heat sensor so if I was going all the way I threw in the new stick too. Yes, you're going all the way in, so really if you follow the fix it instructions its easy. I would do it again in a minute. Biggest worries don’t drop the screen.
Answer to "Can I add a PCIe SSD to my iMac 5K (Oct 2015)?"Is there going to be a Firmware update to stop the bottlenecking on the 15,1 27” iMac?