Bioshock needs a lot of help at the moment. Hopefully, much of it will be addressed in future patches.
VSYNC, as already mentioned, doesn't seem to work properly with triple-buffering.. which causes poor performance.
The DX10 path also causes largish drops in performance with very, very little improvement in visuals (slightly sharper shadows, some slightly improved fog effects, etc.).
Even though you're on Vista with DX10, I strongly recommend using the DX9 path in the game as this should almost double your framerate with little loss. The DX10 additions are very small and not quite optimal yet.
Good luck and enjoy the game! We're all keeping our eyes open for game patches and driver patches to help address the two issues above.
VSYNC, as already mentioned, doesn't seem to work properly with triple-buffering.. which causes poor performance.
The DX10 path also causes largish drops in performance with very, very little improvement in visuals (slightly sharper shadows, some slightly improved fog effects, etc.).
Even though you're on Vista with DX10, I strongly recommend using the DX9 path in the game as this should almost double your framerate with little loss. The DX10 additions are very small and not quite optimal yet.
Good luck and enjoy the game! We're all keeping our eyes open for game patches and driver patches to help address the two issues above.