Originally posted by macTak While the card won't be faster in-camera, it is worth noting that it can be faster transferring images to the computer, namely if you use a UHS card reader (hardly out on the market yet but they will be soon).
Fair point. As image files grow (think video?) the read rate becomes more of a factor.
But the interface then becomes an issue. USB 2.0 (which is all I have on computers that I hope will last for another couple of years at least) has a max of 60 MBps and is shared among all ports supported by the given controller. Even the most basic protocol takes 10-15% of that and USB hard drives are even slower.
I'm not sure what other overhead exists in the SDXC cards but it appears that a USB 3.0 interface may be needed to take full advantage of the higher speeds we're seeing on the fastest cards.
I expect I'll add a USB 3.0 adaptor and hub to one desktop some day but I think my laptops will be stuck at 2.0 for their useful life.
So ..... I don't think those extra conductors will be helping me much in the near term. In the long term, I will further think that a 16GB super-duper-speed card I buy today will be too small. I'll have to buy new, big cards anyway, I suspect.