Seems like a general WebGL issue -- I've seen most WebGL examples hang up or freeze on integrated graphics / Intel graphics but they always run absolutely smoothly on "full-blown" gamer-like GPUs (nVidia etc.) Unless your nVidia is on a MacBook but running Linux instead of OSX und thus odd drivers.
Worked great for me until I switched tabs back to HN to read comments. My screens instantly went black while my video card driver thew up all over my desk.