Damien, are you used testing aliased graphics using Direct2D? It is suprising if Direct2D is slower for aliased graphics, compared to GDI. That indicates a fundamental inefficiency in the design. The problem with the Direct2D tips in the video, is they almost all rely on some kind of caching. That is fine for a few primitives but usually doesn't scale well, unless you can reuse resources across primitives (not your case, I think).