hi everybody again.
I think I saw a post about this already, but I couldn't find it with google on avrfreaks.net :(
However...here is the problem:
I'm trying to record 96khz stereo audio (16 or 24 bits) to a SD card. Furthermore, the idea is to record 2 stereo channels (4 mono streams).
I once did a test with the SD card and I could get about 1.1MiB/seg write speed. I don't remember if i used fat or plain 'dd'.
Now i'm using vfat and I cant get more than 0.35MiB/sec which is too slow for my app. This happens on two SDs, one Kingston and the other one SanDisk. I couldn't try with other ones.
However, read speed is better than 2.5 MiB/sec.
I checked the MCI clock and it seems alright (I get 15MHz).
Maybe the vfat layer is slowering things down, but I think there must be something to do to get higher write speeds since windows can do 2.74MiB/sec when writing on the same SD. Of course I'm not expecting to compare a PC with AVR32 embedded linux, but what I mean is that it should be something doable.
btw, i'm using kernel 2.6.23