Simple question. Which is faster. Alphablending in 16 bit or 32 bit ??

I believe it depends on the API and the video card that it is being performed on. DirectX at least handles alpha blending for the most part in hardware acceleration. A lot of older cards were optimized for 16 bit and so will perform almost any operation in 16 faster, including alpha blends.

I am talking about Alphablending in DirectDraw.
(= no hardware acelleration).

acceleration that is