I needed to replace my original HDD with an SSD. I wasn't sure what format would fit onto my motherboard. The warranty had expired and their tech support wouldn't or couldn't help me pick out a proper one because it was a modification. So I called Mr. PC Doc and he was able to choose a Samsung that fit fine and really boosted the performance. My old system was okay, but I was interested in the 5K monitors coming out (for landscape photography), and I didn't want to spring for a new system until desktops can comfortably handle it and the prices come down. Therefore I needed to get another year or 2 out of my current setup.