What’s the best way to speed up OS X? My work has 2011 iMacs that are way faster (UI wise) than my current iMac, although they have older generation processors, older generation graphics cards, and HDD’s rather than my custom fusion drive. They’re running the same OS, still logging in happens almost instantly, and the UI is incredibly responsive. I’ve used some functions from Clean My Mac, but even still, I’m not getting anywhere near the speed they’re achieving. Perhaps they’ve been optimized, but if so, how?