In my game, Star Ranger, I used low poly models, had a generic (virtual calls) scene graph, used C++ to talk directly to DirectX, and I can't maintain vsync.

That is, when I turned vsync on, sometimes it'd drop below 60fps & so the game stutters for a little bit, which I didn't think was possible w/ C++.

I think it was because I didn't bother to batch any of my models, using a separate vertex buffer for each. I was gonna re-write it (doing better GPU management) w/ XNA, but just got side tracked.

Wouldn't that be cool? An XNA game performing better than C++ ?