>My take is it is not worth the money today to get the latest >and fastest CF card because your camera's processor is the >limiting factor rather than write speed to the card. The move >to XQD with the D4 and future cameras will enable much faster >write speeds as future generations of cards are developed.
I agree with you, but a comment on the speed.
I think a lot of people see 6 fps, see a buffer size of 17 and think it fills quickly.
First, the way I read it (page 104 of the manu) the maximum frame rate for full frame FX is 4fps, period. It would appear that 5fps and 6fps is for crop mode only, which means smaller image, and so larger buffer.
The buffer for 14 bit lossless compressed is 17 shots. Assuming we are at 4fps (if I'm not misreading the manual), everyone thinks "4 seconds". But not.
The size of the lossless compressed is 41MB (also from the manual page 436).
Assume you get a 90MB/s card, and it really manages 82MB/s since a lot of it is hype but mostly so I can do the math. That means ever second you write 2 shots to the buffer.
This means at 4fps you are really filling the buffer of 17 shots at only 2 per second, so you run out at about 8 seconds.
To me 8 seconds is a LONG time of individual shots. I'm trying to think of something - birds, sports (e.g. a wake board jump, kit surfer jump) -- that's a LONG time to just flat out shoot while keeping on the target.
If my math is right, and you believe card speed, this is the approximate number of 1x FX 41MBS lossless compressed images you can shoot before the buffer fills:
And that's best case -- the 4fps drops for VR, slower shutter speed, auto-ISO (that's a bit of a surprise), or low battery. I think it may also slow depending on focus mode but the manual doesn't mention that.