stick wrote:There were lots of posts from people testing various cards last year. I seem to remember that the sd card controller maxed out at 20 mb/s. That was with the original spec model B.
The default bus speed is 50MHz, and you get 4-bit per cycle, so theoretical maximum is 25MB/s. You probably won't achieve more than about 22MB/s due to overhead.
I have seen people overclocking the sdcard bus if you wan't to live dangerously.
But, headline max read or write speed (and so sdcard class) isn't what makes the system responsive, it is the random access 4K benchmark.
Sandisk cards tend to be good at that.
Assuming you are streaming Blu-rays from the network, then sdcard speed has little effect. Overclock, network settings (nfs with best options) and using audio passthough will have much more effect.
It does speed up the UI and browsing though. (And a USB install can help even more).