virtumvp does not improve performance. It has a new type of vsync and is supposed to help to make your game feel smoother. I tried it and in games I needed to use an fps limiter, skyrim and metro 2033, it worked fine. In most games it made it feel like I was getting 25 fps when fraps said 130. My suggestion is don't use it. Maybe with Hawsell Lucid will iron out the remaining bugs and it will be worth using, but not now.