Something to consider in your thoughts of Card access ... is the default Card Speed itself. Some cards are defaulted to 4x speed, whereas others are being advertised at speeds all of the way up to 60x (you can see these on
www.tigerdirect.com, under the SD card section).
Whatever you use for testing purposes, you'll want to ensure that you use the exact same speed for benchmarking.
(though to answer your question, I don't *think* that the processor speed itself is a major part of card access, except of course, in what the handheld is trying to DO with the data as it pulls it off of the card).