Do you enable v-sync ?

No, it kills performance unless you can handle it.

Yes, always. I also force it for games that don't have the option in their settings.

I almost always do, perhaps out of old school habits???

I run a FX-8350 at stock 4 ghtz
16 gigs ddr3 1866
Asus Crosshair Formula Z
2 R9-270X 4GB in crossfire
All ssd drives.