Yes I understand your logic Martin from what I  know it seems regardless of Jpeg or raw files reading to the camera buffer and speed of all reading and writing to the card may well be quicker in faster cards What I am saying is that it does not seem to make a difference to the camera performance in frames per  sec and cycle rates are unaffected the camera is rated at say 5 frames a sec thats all you will get regardless...

If you are saying that faster cards improve this I would like to know where this data is, as I have not found that the frame rate will improve which for me as a Bird in flight photographer being of special interest to me..  I have had to accept the limitations of my 5D at 3fps and I  would have to buy a 1Dmk11 or 111 if  I wanted to improve on this aspect..  I have no idea if this is another story for say Olympus or Nikon Owners or any other camera maker..

Danny O'Byrne  http://www.digitalartzone.co.uk/

"All the technique in the world doesn't compensate for the inability to notice" Eliott Erwitt