Hi there, I'll try to describe this issue as best as I can. My mouse freezes for a second or two every few seconds. I orignally thought it was the mouse or USB. The cursor stops, clicks by itself and sometimes disappears or jumps to another display. I then discovered that windows in finder and safari change slightly as the computer lags. It looks like everything gets selected for a second and goes back to normal. This slows down the computer to a point that I can't work. I can also hear my external drives spinning in the background for no reason. Maybe that's unrelated. This has started yesterday, since then I updated the OS and tried everything I could find on the internet. At this point I'm ready to jump off a bridge :S OS: 10.12.4 computer: Mac Pro late 2013 More info: this problem is intermited it comes and goes and gets worse to a point that the computer is unusable.