USB 2.0 with bogus Data Rate

Julian Elischer julian at elischer.org
Mon Mar 21 15:32:49 PST 2005



Carlos Silva aka|Danger_Man| wrote:

> Hi hackers,
>
> I have a little problem with my external disk drive, my data transfer 
> rate is 1.000MB/s.
> I have USB 2.0 so the rate is larger, right?
> Somebody has an idea how to enlarge the rate?


the data rate is bogus because it is printed by the scsi/cam code
which doesn't know about USB speeds.

This has been improved in 6.x and may flow back to 5.4..
in the meantime, ignore that number and use
dd if=/dev/da0 of=/dev/null bs=64k
to see what your rate really is..

>
> Regards,
>
> Carlos
>
>
> osiris# dmesg | grep usb && dmesg | grep da0
> usb0: <Intel 82371AB/EB (PIIX4) USB controller> on uhci0
> usb0: USB revision 1.0
> usb1: <VIA 83C572 USB controller> on uhci1
> usb1: USB revision 1.0
> usb2: <VIA 83C572 USB controller> on uhci2
> usb2: USB revision 1.0
> ehci_pci_attach: companion usb1
> ehci_pci_attach: companion usb2
> usb3: EHCI version 0.95
> usb3: companion controllers, 2 ports each: usb1 usb2
> usb3: <EHCI (generic) USB 2.0 controller> on ehci0
> usb3: USB revision 2.0
> GEOM: create disk da0 dp=0xc2d96850
> da0 at umass-sim0 bus 0 target 0 lun 0
> da0: <USB 2.0 Storage Device 0100> Fixed Direct Access SCSI-0 device
> da0: 1.000MB/s transfers
> da0: 190782MB (390721968 512 byte sectors: 255H 63S/T 24321C)
> osiris#
>
> osiris# usbdevs
> addr 1: UHCI root hub, Intel
> addr 1: UHCI root hub, VIA
> addr 1: UHCI root hub, VIA
> addr 2: USB 2.0 Storage Device, Acer Labs
> addr 1: EHCI root hub, (0x1106)
> osiris#
>
> osiris# camcontrol devlist
> <USB 2.0 Storage Device 0100>      at scbus0 target 0 lun 0 (da0,pass0)
> osiris#
>
>
>
>
>
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