Performance problems with external USB drive

[Matthias]

Hi,

I have an Samsung laptop which boots a kubuntu (breezy) from an external 
usb drive.
This drive is usb 2.0 capable and so are two of the four laptop usb 
controllers.
However, this drive is very slow here [0]. I noticed that the drive is 
much faster when it is connected to a knoppix installation on another 
computer of mine. Unfortunately I cannot test this again at the moment 
as I don't have access right now to the other computer.
It was also slow when I connected it to the laptop when it was booted 
from the internal drive, so I think it does not matter, that the whole 
system is now booting from this external drive.

I did research in several Ubuntu-forums and mailing lists but only found 
suggestions regarding async/sync and usb 1.1/2.0.
Afaik ~8mb is significantly more than what usb 1.1 is capable of, so I 
think v2.0 is used.
mount [1] tells me nothing of async but I included it in /etc/fstab [2]. 
I also did mount -o remount,async on /dev/sdaX and /dev/mapper/crypto* 
respectively but it doesn't change anything. Why does async not appear?

As some users with similar problems suggested to check whether the right 
kernel moduls are loaded (ehci_hcd is the first to load etc)...this 
seems to be correct here as well.

Does anyone have an idea what I can test next? I also included the 
shortened output of /proc/bus/usb/devices [3] and dmesg [4].

Any help is very appreciated!

Regards,
Matthias

P.S.: I cannot find this thread right now but iirc there was a similar 
problem that I heard of, when some daemon was running and KDE was used. 
The solution there was to simply shut down that daemon but I even can't 
remember where I read it...

[0] # hdparm -tT /dev/sda
/dev/sda:
  Timing cached reads:   1288 MB in  2.00 seconds = 643.78 MB/sec
  Timing buffered disk reads:   24 MB in  3.01 seconds =   7.97 MB/sec

[1] # mount
/dev/sda2 on / type reiserfs (rw,noatime,notail)
proc on /proc type proc (rw)
usbfs on /proc/bus/usb type usbfs (rw)
/dev/mapper/cryptohome on /usr type reiserfs (rw,noatime)
/dev/sda4 on /media/sda4 type reiserfs (rw,noatime)

[2] # cat /etc/fstab
<file system> <mount point>   <type>  <options>       <dump>  <pass>
/dev/sda2 / reiserfs 		notail,async,noatime    0       1
/dev/mapper/cryptohome /usr 	reiserfs async,noatime  0       2
/dev/sda4 /media/sda4 reiserfs 	async,noatime           0       2
/dev/mapper/cryptoswap none swap sw,async,noatime	0       0

[3] # cat /proc/bus/usb/devices
T:  Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  2 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=0d49 ProdID=3100 Rev=77.f8
S:  Manufacturer=Maxtor Corporation
S:  Product=Personal Storage 3100
S:  SerialNumber=508010009519
C:* #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr=100mA
I:  If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage
E:  Ad=01(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=82(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms

[4] # dmesg
[4294670.038000] ehci_hcd 0000:02:06.2: USB 2.0 initialized, EHCI 1.00, 
driver 10 Dec 2004
[4294670.067000] ohci_hcd: 2004 Nov 08 USB 1.1 'Open' Host Controller 
(OHCI) Driver (PCI)
[4294670.266000] usb 1-1: new high speed USB device using ehci_hcd and 
address 2