Curious why vsync on, severely hinders performance?

[Victor B. Gonzalez]

Hello,

I got the Nvidia binary 304.32 on KDE 4.9.00 on Fedora 17. KDE desktop effects 
run pretty flawless at 100+ FPS no matter what I do **but** the second I 
enable vsync on in desktop effect settings, FPS can drop to a choppy 30FPS. 
Why does this happen?

Not a solid 30 FPS but a choppy 30 FPS.

With vsync off, no matter what I do the FPS is at or above 100 FPS **but** if 
I just enable vsync, performance drops to a near 30 during some effects and 
it's very noticeable. I somewhat can't believe it :(

Why could this be happening?

-- 
Best Regards
Victor B. Gonzalez