Info: Mac Pro 5,1, 3.46 ghz, 8 core. 36 gb ram. Nvidia 970 (Not flashed). Upgraded with OSXWIFI + bluetooth 4.0. Any one else having issues with mouse stutter in 10.12.4? I think after I upgraded that is when it started. It affects both my apple Magic Mouse (old kind) and my Logitech wireless RF mouse. My Magic Trackpad is not affected, which I thought was kind of weird. At first I thought it was maybe my USB 3.0 card so I removed it, still stutters. And I mean bad. The mouse will just slow to a crawl for several seconds, seems to only do it when the machine is thinking. Like just opening safari. Does not do this in windows with the same mice. Any help would be appreciated. Thanks.