I'm not sure if I should post this here or in the Mac Mini forum... Here is my setup: Late 2012 Mac Mini, with 400GB iTunes library on USB 3 external drive Apple TV 3 They are connected by wired gigabit Ethernet. So my library used to be on the same internal boot drive of the Mini, but because I was running out of room on that drive, I decided to move it to a USB 3 external drive. Since then, 7 out of 10 movies will stutter a lot during playback. The movie will also seem to slow down, then speed up very quickly to catch up to itself. It never did this when the library was on the internal boot drive. And also, when watching a movie, the Mini isn't doing anything else except running iTunes. Is there an issue with having the iTunes library on an external drive? I wouldn't think so. The external drive is a USB 3 enclosure with a Seagate 1TB 7200RPM drive inside. I would see that there might be an issue if I was wireless, but I am wired with gigabit. Oh, and the external drive is directly connected to the Mini, it is not connected with a USB hub. Any thoughts?