slow USB transfer speeds

farcusnz · December 1, 2011, 4:42pm

I’ve noticed since installing a clean install of Opensuse 12.1 64 that when transferring media files (usually video files) to my usb stick that I am getting pretty slow transfer speeds.

In Opensuse 11.4 files transferred at approx 8 - 9 mb (according to the notifications panel).

In 12.1 they start out pretty quick but then slow down.
While a file might transfer at 8mb for a few seconds it usually slows down to on average 1mb. During the transfer the speed will vary between about 600k and 4mb.

What might be causing this slowdown?
I dual boot with win7 and in that OS files transfer at about 8 - 9mb also.

Is there some kind of file scanning going on in 12.1 that might be slowing things down.
Using KDE btw

caf4926 · December 1, 2011, 5:40pm

I get a slightly different situation.
Where the transfer is made and a notification popup says transfer complete. But it’s not, this I know because:

It’s just too quick
The USB is still working

But overall,kde is working better in 12.1 than 11.4
Gnome, somehow is even better still.

farcusnz · December 1, 2011, 5:48pm

I get the same issue in addition to the slow transfer speed.

Notification says transfer is complete but I can see the usb stick is still working for about a further twenty seconds afterward. I had this behaviour in 11.4 as well though.

The transfer speeds now really are at a crawl compared to previously but I’m not sure where to look.

caf4926 · December 1, 2011, 6:21pm

My speeds are ok

But the file transfers are subject to paste and verification or some such thing, I just can’t recall the exact terminology.

farcusnz · December 1, 2011, 6:36pm

been having a bit of a play and noticed of the three usb sticks I have on hand

an ADATA stick formatted at fat32 gets pretty good and consistent transfer speeds of around 7 or 8 MB

A Silicon stick formatted at FAT (16) and a store brand stick formatted at FAT (16) have severely degraded transfer speeds.

Reformatted these two to Fat32 and the transfer speeds have improved somewhat to about 4 to 5 MB.

It seems KDE 4.7 / Opensuse 12.1 is a little more fussy about dealing with its USB transfers than earlier versions.

In 11.4 I got similar transfer speeds on all three sticks.

robin_listas · December 1, 2011, 7:18pm

On 2011-12-01 18:46, farcusnz wrote:
> In 11.4 I got similar transfer speeds on all three sticks.

Compare the mount options used in 11.4 and 12.1.

–
Cheers / Saludos,

Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)

farcusnz · December 1, 2011, 7:30pm

devices are automounted on insert.
Beyond that I’ll need a little more guidance.

robin_listas · December 1, 2011, 8:58pm

On 2011-12-01 19:36, farcusnz wrote:

> devices are automounted on insert.
> Beyond that I’ll need a little more guidance.

The output of the command “mount” tells you how things are mounted. You
have to do that on both systems and compare. If you don’t have both
installs, somebody else has to do it.

For example, using gnome on my system:


11.4
> /dev/sde1 on /media/SANDISK_2 type vfat (rw,nosuid,nodev,relatime,uid=1000,gid=100,fmask=0022,dmask=0077,codepage=cp437,iocharset=iso8859-1,shortname=mixed,showexec,utf8,flush,errors=remount-ro,uhelper=udisks)
12.1
> /dev/sdb1 on /media/SANDISK_2 type vfat (rw,nosuid,nodev,relatime,uid=1000,gid=100,fmask=0022,dmask=0077,codepage=cp437,iocharset=iso8859-1,shortname=mixed,showexec,utf8,flush,errors=remount-ro,uhelper=udisks)

–
Cheers / Saludos,

Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)

farcusnz · December 2, 2011, 3:45am

12.1


/dev/sdb1 on /media/A-DATA UFD type vfat (rw,nosuid,nodev,relatime,uid=1000,gid=100,fmask=0022,dmask=0077,codepage=cp437,iocharset=iso8859-1,shortname=mixed,showexec,utf8,errors=remount-ro,uhelper=udisks)

unfortunately I no longer have an 11.4 install

the only difference between your and mine is that I am missing “flush”
Would this make any difference?

martin_helm · December 2, 2011, 1:19pm

This is a bit unrelated to the other posts, but you should not forget
that when you copy a lot of cache is used and the transfer speeds are
very unreliable compared to what really happens. On my systems several
hundred MB are cached (if I copy half a GB the transfer ends after a few
seconds while the USB is of course still heavily working the point when
it really ends you can see by invoking “sync” in a terminal).

If you want to see the real write speed you can do an uncached copy with


dd oflag=direct if=largefile of=/media/usbstick/largefile

of course you replace largefile with a real file name and
/media/usbstick with the real path to the usb drive.

farcusnz · December 6, 2011, 5:26pm

seems reformatting the usb drives did not solve my problem as it still presents itself more often than not.
latest observations
Transferred a 350mb video file from NAS drive over wireless G to laptop took approx 90 seconds
Transferred same file from local hard drive to usb pendrive took approx 150 seconds.

Now this just seems wrong to me. Surely USB 2 is much faster than wireless G?

Also noticed that launching programs while file is transferring to USB is not possible.
Something is choking. Tried launching Firefox while transfer in progress but Firefox refused to luanch until approx 20 seconds after device notifier told me transfer was complete.

No such problems launching apps when transferring over wireless from NAS drive.

caf4926 · December 6, 2011, 6:37pm

Also noticed that launching programs while file is transferring to USB is not possible.
I too have seen this. Seems like a bug

robin_listas · December 6, 2011, 8:13pm

On 2011-12-06 18:46, caf4926 wrote:
>
>> Also noticed that launching programs while file is transferring to USB
>> is not possible.
> I too have seen this. Seems like a bug

The programs reside in the USB or in aan internal KD?

–
Cheers / Saludos,

Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)

robin_listas · December 6, 2011, 8:23pm

On 2011-12-02 03:46, farcusnz wrote:

> unfortunately I no longer have an 11.4 install

My 11.4 adds a “flush” there. Man mount says:

flush If set, the filesystem will try to flush to disk more early
than normal. Not set by default.

I’m unsure of the effect.

–
Cheers / Saludos,

Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)

farcusnz · December 7, 2011, 4:46am

Think this might be the bug

https://bugzilla.novell.com/show_bug.cgi?id=719416

seems to be something to do with the opensuse modified kernel.

caf4926 · December 7, 2011, 5:12am

Yep
Looks like it

oldcpu · December 7, 2011, 7:25am

Interesting … hopefully we will see the fix in the next (and first) 12.1 kernel update … I note they posted a work around in that bug report:

workaround:


echo madvise > /sys/kernel/mm/transparent_hugepage/enabled

brunomcl · December 8, 2011, 6:54pm

Just to be sure, what is the output of dmesg after you insert the pendrive and after the file transfer? You should see the driver in use, ehci_hcd for USB 2.0 and something else (ohci IINM) for USB 1.1. The same pendrive use different drivers (or won’t even ennumerate/connect) depending on which port it’s connected to, i.e., in defective front panel USB ports or in a good-quality one in the back of the motherboard.

claudebucher · February 8, 2016, 3:05am

garbage… if you want dd to measure the actual write speed you have to use

/ # dd conv=fsync if=/dev/zero of=/media/0123-4567/500M bs=1M count=500
500+0 records in
500+0 records out
524288000 bytes (524 MB) copied, 11.8357 s, 44.3 MB/s

conv=fsync

(yeah yeah, i know, the thread had been inactive for ever… well got across it a few days ago and started looking into using dd for write performance measurement… that way it works, no need to find some file to copy over, dd does it all)