How to draw a bitmap to Direct3D backbuffer more efficiently?

Question

As far I know, with Direct3D 10 there are 2 ways to draw a bitmap on to the back-buffer:

1. lock the back-buffer's surface, copy the bitmap to the surface, unlock the surface.
2. lock a texture, copy the bitmap to the texture, unlock the texture, and let the texture go all through the render stages, and finally reach the back-buffer.

Now I have a bitmap animation, that is, each bitmap is displayed only once. Either way a bitmap is send to GPU and discarded. It seems that the 1st way should be faster, but I'm not sure. And worst, I can't test it myself now...