Hi,
I'm developing an USB HighSpeed Host Driver Controller for a ppc4xx. As Mass Storage Device I'm using a SanDisk Cruzer, 8GB size. I'm detecting that for 128KB data per read/write transaction, in order to have best performance I could perform a Read procedure with 8 qTDs (16KB/qTD, only one iteration per transaction) at 32MB/s, instead of Write Procedure where I was able to reach the best speed rate using 4 qTDs (always 16KB/qTD, then 2 iterations for transaction); setting a number of qTDs bigger, speed rate goes down. Could it be due to USB key type? Or Could anyone explain the different behaviour of async scheduler? Thanks in advance
