Ever since I upgraded to 10.12.4, Chrome freezes the entire computer on many sites for about 10 seconds with the spinning beachball/pinwheel. An (unfortunate) example, but there are many others: https://twitter.com/realDonaldTrump Safari doesn't have this problem. I have tried disabling all extensions, a new profile with no extensions or anything, and it doesn't fix the problem at all. I have tried all available versions of Chrome (Canary, etc.) I believe I have isolated this problem to macOS 10.12.4, because I have another Mac on 10.12.3 which did not have this problem. As soon as I updated to 10.12.4, it did. I believe the presence of HTML5 videos autoplaying might have something to do with it, as by blocking these I am able to somewhat improve performance and prevent freezing. But I'd rather use safari than deal with the hassle of custom blocking things on every page I want to see.