Originally Posted by Freddy_Bobbins
as far as i know, ur gpu has two buffers the one u see on the screen and the one it is writting to. when ur screen goes to grab the next frame, it just switches the two buffers and ur gpu will write into the, now, blank buffer. but when ur screen looks for the next frame(60 times/sec @60hertz) and its not ready, i has to skip the buffer swap(if vsync is on) this then makes ur screen only show 30fps because it is only showing a frame every other time it looks for a frame.but when u triple buffer, u ALWAYS have a frame ready to be shown so u can then more easily obtain 60fps or higher.
Something about all that here: http://en.wikipedia.org/wiki/Triple_buffering
Describes why two buffers may not be enough, and in different situations why a triple buffer is better, etc.
Good information, but very generalized. Wikipedia really needs to get on the ball with making stuff easily understood (with more diagrams or something.)