You are correct Dan, but there are now adapters you can purchase as a workaround for this issue. I almost went this route before deciding on a used MBP SSD instead out of cost considerations. A simple google search will give you a list of prices and configurations.
I can confirm all models in this line include the connector, as the one I upgraded was the very base model and it was indeed right there on the back of the logic board. A screw to secure the SSD blade was not included, however, so you will need to source your own if you want to protect it from becoming dislodged if you ever bump or move your iMac around.
Yes you do. I just finished this exact upgrade and it was very easy. The only hitch was finding a screw to secure the SSD blade to the logic board as none was included (obviously) I ended up pulling a housing screw from the HDD I replaced with a 2.5” Samsung SSD, which was the perfect diameter but screw head itself was a little small for a snug fit so I added a washer just to be sure.
Wrong, Dan. I just finished upgrading my parent’s late 2013 21.5” that most decidedly did NOT come with a Fusion drive and indeed the connector was right there on the back of the logic board where it should be. As to the original poster’s question: I used a SanDisk SD6PQ4M-256G-1021 I got off eBay for 60 bucks including shipping. Running OSX and Applications off that and replaced glacially slow HDD with a midrange 512GB SSD for media storage like photos, music and videos. Also bumped RAM up to 16GB and did a fresh install of latest Catalina build. Thing boots just as fast as my 2018 MBP now should be good enough for my folks for another 6 years. The only thing lacking is the non-UHD display, but my folks are in their 70’s and don’t care about that. Total investment including adhesive strips and opener tool: about 200 bucks. My folks were ready to plunk down another 1200 bucks for a new model. Sorry, Apple. THANK YOU, iFixit!
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