These statements aren''t, as the Anonymous Poster so eloquently put it, "Full of shit." Instead, they aren''t quite specific enough. 32 bit is usually faster than 24 bit color because the pixels are aligned on 4 byte (ie 32bit) boundaries and processors and video cards tend to like that a LOT more than 24 bit which usually requires all kinds of extra addressing since 3 bytes doesn''t fit very nicely into 4 byte addressing.

As far as whether 32 bit is faster than 16 bit, it''s hard to say. I would think that it''s not likely. 16 bit is probably faster.

cheers to jaxson for that
and no it''s not a full of shit atatement.
Your video card will not support 24 bit colour in fullscreen 3d mode. It will support it for windows but not in fulscreen.
and as for the faster access bit, what is windows? it would be a 32bit operating system. Most current hardware runs on a 32 bit memory address bus so sending anything less than that has no optimisations anymore...
The blocks of data have to be split up, so that gives you slower memory access..

In justifictaion of the second statement, if the prog is set to run using 32 bit color and you try and run using 16 bit it has to convert between the two all the time which causes the prog to slow down. Believe me on this I''ve found this out myself.
It also does the same thing the other way around and is slow for the same reason so set up your prog to use the current colour depth that you have your desktop set to 16 or 32 bit.