The article Slow USB 2.0 mass storage transfer rate suggests that this might be a problem of the device getting mounted by default with the sync option :
Do you have a "Devices" Icon on your
Desktop?
If so, open it. If not, try opening
media:/ in konqueror.
Selct the device then -> Properties ->
Mounting(tag) and uncheck the
Synchronous box. (This gets
remembered, so you should only need to
do it once per-device).
Some more ideas come from the bug-report Write through on external hdd making writing very slow
- you change to async at runtime by 'sudo mount -o remount,async
/dev/sda1' (or whatever your mounted
partition(s) is/are)
- you create an fstab entry for sda which mounts it async (this requires
that the device is always plugged in
at boottime)
- you change 'sync' to 'async' in the pmount source and rebuild the package
See also the discussion in the article as regarding pmount, if this applies to your system.
Another magic solution comes from USB 2.0 slow write but fast read, solution yet? and involves re-mount:
When I mount a USB drive on /dev/sdc1
with the following line
/dev/sdc1 /mnt/sdc1 auto sync,noauto,user,exec 0 0
in /etc/fstab, and try to copy a 5.2
MB file to the drive from the local
hard disk, then after an entire
minute, 244 KB have been transferred.
Copying a 29 MB file from the external
drive to the local drive takes about
10 seconds.
Then if I unmount it, change the line
in /etc/fstab to
/dev/sdc1 /mnt/sdc1 auto noauto,user,exec 0 0
then copying the 29 MB file to the
external disk takes an unnoticeable
fraction of a second. Same with
copying to the local disk from the
external disk.
See this article and the reference to "usbtree". It tells how to check if the usb is functioning as 1.1 or 2.0 :
Linux and USB 2.0.
Just to clear up some possible misconceptions about USB.
First there are four speeds. There is low speed of 1.5 Mb/s (USB 1.0), full speed of 12 Mb/s (USB 1.0), Hi-Speed of 480 Mb/s (USB 2.0) and SuperSpeed of 5.0 Gb/s (USB 3.0).
People tend to confuse speeds and versions of USB standard. Usually devices are made to the newest standard even if they don't need the maximum speeds provided by that standard. There are lots of USB 2.0 devices which use 12 Mb/s or 1.5 Mb/s because they don't need higher speeds. As USB 3.0 spreads, there are going to be lots of USB 3.0 devices which won't be using the SuperSpeed introduced with USB 3.0 standard. So while OP probably considered 5 Gb/s as speed of USB 3.0, all other speeds are also USB 3.0 speeds.
Another point are the cables. USB 3.0 provides new types of connectors and cables which are going to be needed for SuperSpeed use. USB 3.0 cables are mostly compatible with USB 2.0 connectors, but there are couple of differences. USB 3.0 B male connector is not compatible with USB 2.0 female devices and can't be plugged in!
The third point are unit loads. Standard unit load for USB standard up to 2.0 is 100 mA and single port can provide up to 5 unit loads. For USB 3.0 it has been increased to 150 mA and up to 6 unit loads per port. That means that USB 3.0 devices are going to be expecting more power from computer. On the plus side, that means that USB 3.0 compatible phones and other similar devices will be able to charge faster, but on the other hand, poorly designed USB 3.0 devices may have too little power to work if they are connected to USB 2.0 port. This most likely isn't going to be a problem in the transition period, but later it could be.
So in the end, if you want to have for example a flash drive which uses USB 3.0 SuperSpeed, you'll need USB 3.0 port on the computer (and if it is on an expansion card, the card will need to use PCI-E), USB 3.0 cable which will connect drive and port and USB 3.0 drive which supports SuperSpeed. If one of the 3 components isn't USB 3.0 rated, it will slow down the whole system.
Best Answer
Most tech sites (annandtech, techreport, etc) include USB comparisons in their motherboard reviews. For example techreport in this review uses CystalDiskMark to compare read/write speed of various controllers. They use an external drive to test the USB speed. From the testing methods page:
Find a site you like and use the same tools.