Just chiming in to log the exact same problem as everyone else. Fresh install of windows 10, vive, and steam, and I get 100% processor usage at all times when vive wireless is working, even in steam VR home which is simple. VR compositor, VR tours, and System are my main users. PResumably System is the driver interacting with the kernel in windows 10, and it's usually down around 10% or lower. So I don't believe this is an issue of data compression taking too much CPU. This is some other problem. Games all run just fine when wired, of course.
Also, this thing does not work on windows 7. a travesty. Why did HTC put out advertisements claiming it works on windows 7? BAsed on my reading of the internet, to my knowledge, no one running windows 7 has made vive wireless work (that's why I tried this on a fresh windows 10 install).