Originally Posted by rudi (Post 129659)

Secure Digital cards are a lot smaller than CF cards. They have a 9 pin interface rather than a 50 pin interface as on the CF card. This limits them to a 4-bit data transfer bus where the CF card has a 16-bit data transfer bus. This makes their maximum possible transfer speed slower. However, having said all that, I don't think it would make that much difference with most of the consumer or prosumer cameras, in some of the pro SLR's like the Canon 1D it does as these cameras would take advantage of the extra speed.