On Thu, Jul 24, 2008 at 08:49, Andy Green <[EMAIL PROTECTED]> wrote: > > Well, a good rule of thumb for generic 1-bit transfer is divide by 10 > for the max speed in Bytes/sec you could expect, here we have 4-bit so > the peak raw trasfer speed is ~10MBytes/sec *BUT* after Glamo pulls the > data from the card, we have to sit there dragging it into the CPU > memory, on top of card latencies and command setup the speed is way > slower, still a decent ~2MBytes/sec each way IIRC. > > - -Andy
Thanks. This is something I also wanted to know for the choice of a new card. So we may say that up to 10MBytes/s, max speed of the microSD matters. After it should not much. (?) (and looks like 10Mbytes/s is currently what offer rather high end microSD) One more question though : if the card is slow, throughput will be lower, but will the CPU / glamo graphic bus be able to benefit of more resources while the card transfer occur ? Or does it just had to time to wait and CPU / glamo bus are as much busy (or waiting) ? Same question if we lower the SD clock rate. Is it equivalent to having a slower card ? _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community