@LancerX

you need to restrain the fps on your wows. set their maxfps to 40-60 and maxfpsbk to 5-20.

if you don't, then wow will try to max out its fps, not leaving much for anything else. PiP is just resizing windows... which does take some processing power to scale up, but that's brief. if you left enough cpu/gpu by restraining the fps, your PiP should be fine.

let me know how it goes.