Well, depending on your level of patience, any card is fast enough for the 7D. The Extreme III will be "fast enough" for most users.


But if you want to know which card will allow the 7D to hit peak performance, that's a different question. Rob Galbraith hasn't posted his final test results yet, but I expect the 7D would benefit from an even faster card than the Extreme III. I would guess that the Sandisk Extreme IV will about 50% faster.