If you've performed any Adobe updates lately you may have noticed that there is something "constantly" tapping into processing power. After some investigation there's a little .exe that is loaded with some recent updates that is set to be on by default. The darn thing sits there and accesses your drive continually. And, its a deep access, not one of those light tapping ones. I have a TB drive here (two 500G partitioned drives) and I thought I had a problem. All fixed now by doing msconfig/Startup and turning that thing off. It will interfere with your computing experience.

Adobe Photo Downloader 3.0

That's the culprit right there!