Firmware

MB = megabytes/second. Mb= megabits/second. As 1 byte = 8 bits the differences are apreciable.

Davex.

I've got about six of the 1GB Toshiba whites. If I could find somewhere that stocks the 4GB version I wouldn't use anything else. They are only faster at writing to the card though and most cameras can only write at 2-3 MB/s so a faster writing card is not needed. Copying to the computer from the whites I get 12.2 MB/s which is slightly slower than the 12.7 MB/s for the Blue ( I suspect these Blues are the same as the Blacks). I have one 4 GB Black.

The different types are shown on this site link From Invention to Perfection.

The speeds vary depending on the size of the files, for these tests I've used 30 No PEF + JPG (15 of each) = 180 MB most take 14-15 secs. I actually copy to a 200 MB RamDisk so that the HD speed does not effect the result.

shim

I don't believe that 2-3 MB/s figure is correct or relevant for Pentax dSLRs.

The speed of the memory card does make a difference to how quickly the camera's buffer is written. I particularly noticed it with my *ist DS.

With the DS, a full buffer (after continuous RAW shooting) with the white Toshiba card is written several seconds more quickly than an average bog standard card, about twice as quickly in some cases. I found an A-Data card that was even slightly quicker than the white Toshiba in-camera. So certainly the speed of the card speed makes a difference in practice with this camera (and expect some other models too).

It is not so important with the K10D and K20D as they don't fill up the buffer in normal shooting.

Thats where the Sandisk lifetime warranty comes in over the cheaper ebay cards (if anything does ever break). - I've had one that I purchased 18 months ago still working fine and no damage to the hinges - used daily; and have another two for when I go on holidays and need the extra space. Great build quality, and definitely not weak plastic.