apersson850 wrote in post #8978015
They produce about 250 MB/s of image data, so you'll run out of buffer space anyway.
But a faster card will flush the buffer quicker, so there are still advantages.
I have looked and looked for the 7D's write speed and can't find it in any of the specifications Canon has released.
I'd be surprised if it was amuch bove 45MB/s, which means that any card faster than 300x wouldn't make any difference in the camera itself (but it might download to the computer faster).
The reason I was wondering is that I've noticed that the 7D takes longer to display an image right after it's shot. I have image review "off", but occasionally manually review an image. If you do that right after taking a shot, with 7D it won't display it, the preceding image will come up instead. One or two seconds later, the most recent image is available.
So image review isn't instantaneous on the 7D, the way it is on both 5D MkII and 50D.
In order to take full advantage of UDMA download speeds (transfering to your computer), you need to have an UDMA capable card reader and Firewire 800 connectivity. Slower readers can download from the cards, but only at their lower speed rating. USB 2.0 and Firewire 400 are going to take about twice as long to download a card.
I have an Express Card reader for my laptop that's able to do 54MB/s (close to 400x, which is 60MB/s), but it's a bit fiddly to load and unload cards (plus the laptop's single drive fills up fast, so I have to move images off it via a network pretty frequently).