Thank you for your valuable reply.
> As I replied on the Linux newsgroups last night, you need to use larger
Sorry, I did not expect any replies for my issue on the newgroup anymore
as i did not find any for 2 days. So did not not watch anymore.
> We are able to get 22 MB/s on a bulk pipe from an FX2 device
> using the usbfs machinery (which is what libusb uses), using normal
> synchronous requests, just by doing 32k bytes per transfer. We are able
> to get 30 MB/s on the same device using asynchronous requests, by
> submitting several at a time.
This sounds great, We also want to achieve that
I just tried to read more that 512 Bytes with usb_bulk_read (1024,2048,4096,16384)
And it worked. I did not expect that to work. As I remember it did work for me in my place. It
sent me at most 512, or 1024 bytes, which was the hardware buffer size adjusted in the FX2 device.
However In I place 1024 Byte Requests still give best results(about 3.5 MByte/S)
If I request 64KBytes, it drops down to 100 KByte/S.
Do you actually mean using bigger request sizes, which you tell using bigger bufffers ?
Or is bigger buffers something libusb internal. If yes, whats the USB internal default buffer size?
How is your USB library advanced in contrast to the normal one - is it available ?
Attached to this mail, there are the 2 programs I use for testing my datarate. Probably you see something odd :)
Thank you in advance.