The difference was amazing: much much faster. It already had 8gig of Ram (which I didn’t upgrade, though I did consider it). I replaced my old HDD in my 2011 Macbook pro with a 1 Tb SSD from Samsung. Also if you maxed your ram + installed SSD and some much needed new thermal paste did you have a significant performance improvement. So here I am wondering if anyone has done this complex surgery (since everything get's taken out pretty much) and what tools you used / got them from. iFixit is oddly sold out, on both the Tool Kit + Adhesive Stripes. While I have no interest in trashing a perfectly fine machine and I would be insane to do so I can't seem to find a set of proper tool pack for the job. My hard drive will fail sooner or later, the thing took 4-5 days to do a Whole Disk Encryption on a brand spanking new Mojave re-install (and I mean fresh, hard drive wiped and OS re-installed type of fresh). So here is where my dilemma comes in and where I would like some input from others. The other part that surprised me is that it seem's you can upgrade the stock 8GB of RAM to 16GB of RAM. On my quest I found an iFixit article and this is where the fun starts the tools aren't in stock. So I was sitting yesterday looking into replacing the HDD to a decent 1TB SSD from Samsung or Crucial. I have a Window machine so I been using that, but still find myself using the iMac for programming purposes and multimedia. Unfortunately for me the old (original) mechanical HDD is on it's last leg.

Late 2013 imac trim for samsung