V-sync creates a tiny performance drop because it adds a little overhead. That means if you just barely made 60 before then turning on v-sync is likely to leave you at 30 (assuming 60 hz refresh). V-sync will not lock on any FPS between 30 and 60 for a 60 hz monitor and that's how it prevents screen tearing. Also anything short of 60 but above 30 will go down to 30. And if you're below 30 it locks on 15. It exists mainly for people who are going over the maximum FPS their monitor can display.
If I don't have V-sync enabled with Triple Buffering then the screen tearing is absolutely unbearable. There is no reason why this game should be so demanding that my hardware should not be able to run it at a constant 60+ frame rate with V-sync enabled. And I am not talking about 60+ at the minimal graphical settings. My hardware should easily be able to handle this game with the highest settings save for medium shadow quality and no ambient occlusion.
