MedicineMan4040 wrote in post #17933452
So with the 'free' CFast I won't be giving up 14 fps but the total that can go to card without filling correct?
Yep. At some point you'll get a traffic jam of cars unable to join the freeway; because the freeway's only running at 240mph today, so it can't take as many cars as quickly (if that analogy makes sense) 
The raw buffer size is claimed to be about 73 shots with a CF card (at UDMA7, which is around 166MB/s). It's 170 with a CFast card (I assume one at the max available card speed of around 440MB/s write). You probably could do some math to work out the data rate of 14fps raw files vs the various card speeds, but with a 240MB/s card it should be somewhere north of 73.
Basically, if you're trying to store data at a higher rate than your media can record (e.g. shooting raw not JPEG) then the 14fps limit will be the number of shots the camera can store in its internal buffer + the extra space that's freed by writing the first images to the card in the time it takes you to fill the buffer.
An analogy might be a bucket (which you're filling with water from above - these are your shots), and the bucket is draining from the bottom through a tap (this is the shots being written to the card). The more flow you can get from the tap, the longer you can spend pouring water into the bucket before it fills. Also, the larger the bucket (the camera's internal buffer) the more shots you get before you become reliant on the card.
EDIT: In summary, you'll still be able to spray at 14fps for at least 5s (73/14~=5), and at 240MB/s you should be able to record constantly at maybe 8fps (240/30MB raw=8)