Memory buffer / CF card transfer

[richardjjj]

Hi.
I have researched but can find no definitive information on the following so would appreciate any knowledgeable input.

Can anyone advise the CF card specification that Canon use for testing the frame rates advertised for a 7D ?

Assume that, say, a 60MB/s UDMA card is the standard, is there a 'in camera' performance gain from using a 90MB/s card?

If no to performance gain, could a future firmware upgrade address this or is the buffer transfer speed fixed ?

Thanks
Richard

 

[willsphots]

canon says the the 7d can take 15 raw files at 8 fps. i can usually get 25-30 shots at 8 fps i.e. 3 to 4 seconds of holding the shutter release down, with both a sandisk extreme III (30mb/s) and a sandisk expreme pro (90mb/s).

however, the time it takes to empty the buffer is a lot longer with the slower card. using the extreme pro, if i keep the shutter button down, the camera drops to a gallop rhythm (th-thunk-pause and so on) and keeps this up indefinitely. with the extreme III, it starts taking a shot about once every 2 to 3 seconds.

the buffer size and write speed won't be affected by firmware updates. what a firmware update could do is make communication between the components more efficient, but i doubt it will translate into a noticeable performance gain where this is concerned.

 

[richardjjj]

Thanks William.
I understand the buffer size cannot be increased and probably the 'write to buffer' speed is at maximum but cant find anywhere that states what the optimum card spec is.
My experience is similar to your own, that there is a definite advantage with the faster cards however there will be a max performance gain at some point. Just wondering what point this will be.
Also cannot understand why its so difficult to find the card spec that Canon use for thier testing.
Regards