Check out http://isitsnappy.com http://isitsnappy.com (not my app, I've just used it before), lets you measure latency empirically. Set up a loop where you pres

Check out http://isitsnappy.com http://isitsnappy.com (not my app, I've just used it before), lets you measure latency empirically. Set up a loop where you press a key as soon as something appears on screen, and that will give you your end-to-end latency.