Yeah, that's always been the "story". I sometimes mess with that setting a lot and most of the time, for directX things, it makes no difference. There was an exception to that though, on MS Flight Simulator X (running in directX9), turning it ON gave a solid 5-8 fps boost. Tested ON and OFF many times due to me thinking it was weird that it worked. But that was a LONG time ago, on an old 560ti, and i think it was Windows XP or 7 at the time.