I know this has been discussed many times, I guess I jus need a push. Right now I can do one upgrade. I have a late 2013 27" iMac, 8 Gigs of RAM and 1 Tb internal 7200 RPM drive. I do a lot of lightroom and Photoshop work. What upgrade would you do first? Add 8 more gigs of RAM, or add a 256 external SSD? Would I have to do something different for the SSD as far as TRIM control or would that just work? The SSD would be USB 3. Thanks for your input.