Is there a reason you're running the background windows at 30fps? I set my background windows and dxNothing windows all to 12fps, since they're just there for at-a-glance status anyway; it's very noticeable on my older video card and 5x clients at 1080p high detail. Also, if you haven't already configured a "high-detail/low-detail" console variable macro tied to your window switching mapped key, that might be impacting things needlessly.