Well I can quote developers back at you if you like:quote from the article:"Obviously waiting for Vsync before window swapping can cause a slow down. If you take 1.1 frames to draw a scene, then wait for Vsync before swapping frame buffers that means that .9 of that frame is spent doing nothing on the card."or elsewhere:"the ability to squeeze a couple more frames per second is a tweak I used quite often when playing graphically intensive games on lower performance systems. Was there tearing...damned right! Did it speed up the games? Sure did, but when you're getting 15-20fps in your favorite game, anything is an improvement, and the odd graphic glitch is a worthwhile tradeoff!"Obviously you're not going to be worried about framerate if you're getting over 60fps in the first place and in that situation then you should turn on VSync to get the visual improvement if you suffer from tearing. But if you're wanting to improve performance (as most people reading topics about tweaks to systems are) and you have under 60fps, then you should disable VSync, as, I repeat, it will lower actual, real framerate.