is that part of the HID protocol ? I've read *somewhere* that is a bad idea . . . No hands on with it personally, but i do some reading from time to time because its an interest.
Anyways that's really interesting you're getting way worse speeds than mine. Also, I've noticed that most of the time even just sata / pata <-> usb 2.0 bridge chips rarely get above ~23MB/s average total throughput. Thats about half of theoretical, but we also need to consider the 8/10 bit protocol encoding . . . Something else you may find interesting. The other USB port host I believe it is does ~20MB/s writes, and around 11MB/s read when connected to a USB HDD . . . thats reverse of what I'd expect, higher reads and lower writes . . .but there ya have it. On Tue, Dec 9, 2014 at 6:28 PM, ivo welch <[email protected]> wrote: > > thanks, william. I first went an easier route. I did create a 16MB > random file on the host desktop, and rcp'ed it to a ramdisk on the BBB over > usb. I am getting about 4MB/sec. then I went the iperf route. your > memory was excellent, except the -C switch for the client is -c. this also > reports a bandwidth of about 30 Mbaud. > > so, on my simple experiments (linux metal desktop, bbb rev c usb), here > are my transfer speed comparisons (all in MBaud = MBit/s): > > serial over usb : < 10 > mass storage over usb : ~ 20 > ethernet over usb : ~ 30-40 > > theoretical usb speed : ~ 480 > > local eMMC speed : ~ 70 > > I wonder if I can figure out how to send raw messages over USB with > usb_bulk_msg() on the host without a higher level protocol (ethernet, usb > mass storage, serial). has anyone written already a simple "echo" script > for the BBB that just responds to usb_bulk_msg requests and prints summary > info on the console? > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
