Hi, thanks for the reply and suggestions. lsusb shows 3.0, 2.0 and 1.1
root hubs, more tests (ssh to box, use "cp" command) on all the USB
ports give similar times, between 5:00 and 5:45, giving me speeds
approaching 20mbps. The motherboard specs say all rear ports and
headers (for front panel) are USB 2.0 (or 3.0). I see that the 1.1 hubs
use ohci_hcd driver, 2.0 the ehci_hcd, and 3.0 the xhci_hcd drivers,
though this doesn't offer me any clarity about what may be the issue or
where/if I can improve the situation.
Sadly further testing with other boxes is suggesting I have rubbish
transfer rates via USB other places too. And that the above stick will
receive the same file in 2:00 via Windows. Any other suggestions are
appreciated, but at this point it looks like I return the box to it's
owner stating that USB copies will be s l o w . . .
Cheers,
Roger
On 04/07/12 10:01, Derek Smithies wrote:
Hi,
Since we know that the stick does copy quite quickly on a different
box, we "know" the stick is good.
Note that write speeds are invariably slower than read speeds for usb
flash sticks.
However, the listing on the usb devices is the "giveaway".
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10 <<< -- this means that it is usb 1
(seriously slow).
lines like the above suggest suggest that there are usb 1 devices - or
the hub is slow.
I could work out from the listing what the fault is, but it is
simplest to say;
a)take all usb entities off the computer.
a.1)reboot the computer if paranoid
b)ssh into the box from a second computer
c)put the usb device into the usb sockets at the back, which are
directly connected to the motherboard. (rather, are on the motherboard).
***The usb sockets at the back, which are on the motherboard are
most likely to be usb2. The other sockets may, or may not be usb2.
d)now try the file copy operation, which should be quicker.
If not quicker, move usb stick to another socket on the back and
try it. At this stage, it is all bad..
e)now attach other usb devices, and see what the times are - or try
other usb sockets and see what the times are. This tells you which
socket (or devices) are usb 1.
Above is fault finding the simple way.... Delving through listings can
be tedious..
Cheers,
Derek.
On 04/07/12 06:09, Roger Searle wrote:
Hi, I am trying to determine what if anything might be wrong or can
be done on a mythbuntu 12.04 64bit box, write speeds to USB sticks
seem painfully slow. This is true of both front and rear ports and
to different sticks, which will perform much better on other boxes.
As examples, copying of a 700MB iso file is generally taking around
5:30 minutes where as same stick on a "good" box is more like 1:30.
The times I have measured are for the displaying of the file copy
dialog box to disappear, and have shown variations of +/- 30 seconds
however the "bad" box seems painfully/noticeably slow, maybe a third
the rate of the "good" box.
Some info from lshw, lspci and lsusb -v below, can anyone suggest
what I should take a look at from here?
Cheers,
Roger
>>> lots deleted..
_______________________________________________
Linux-users mailing list
Linux-users@lists.canterbury.ac.nz
http://lists.canterbury.ac.nz/mailman/listinfo/linux-users
