low USB tranfer rate with external IDE

[Vlad Skvortsov]

Hi!

I've got FreeBSD 6-STABLE with external HDD enclosure that claims to 
support USB2.0 transfer rates. It is attached via a PCI USB2.0 card. The 
transfer rate I'm getting with this setup is only around 1 Mb/s:

16:20 [vss at bear] ~ > diskinfo -t da0
da0
        512             # sectorsize
        250059350016    # mediasize in bytes (233G)
        488397168       # mediasize in sectors
        30401           # Cylinders according to firmware.
        255             # Heads according to firmware.
        63              # Sectors according to firmware.

Seek times:
        Full stroke:      250 iter in   9.134642 sec =   36.539 msec
        Half stroke:      250 iter in   6.990184 sec =   27.961 msec
        Quarter stroke:   500 iter in  11.123201 sec =   22.246 msec
        Short forward:    400 iter in   3.346094 sec =    8.365 msec
        Short backward:   400 iter in   3.451729 sec =    8.629 msec
        Seq outer:       2048 iter in  12.313245 sec =    6.012 msec
        Seq inner:       2048 iter in  12.321137 sec =    6.016 msec
Transfer rates:
        outside:       102400 kbytes in 101.798916 sec =     1006 kbytes/sec
        middle:        102400 kbytes in 101.800717 sec =     1006 kbytes/sec
        inside:        102400 kbytes in 101.804236 sec =     1006 kbytes/sec

It seems to be limited by the device:

16:28 [root at bear] ~ # camcontrol inquiry da0
pass0: <Maxtor 6 L250R0 BAJ4> Fixed Direct Access SCSI-0 device
pass0: Serial Number
pass0: 1.000MB/s transfers

Here are relevant lines from the dmesg:

16:37 [vss at bear] ~ > dmesg | grep umass
umass0: Myson Century, Inc. USB Mass Storage Device, rev 2.00/b0.08, addr 2
da0 at umass-sim0 bus 0 target 0 lun 0
16:37 [vss at bear] ~ > dmesg | grep usb 
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

16:39 [vss at bear] ~ > dmesg | grep ^uh
uhci0: <Intel 82371AB/EB (PIIX4) USB controller> port 0x1000-0x101f irq 
11 at device 4.2 on pci0
uhci0: [GIANT-LOCKED]
uhub0: Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 2 ports with 2 removable, self powered
uhci1: <VIA 83C572 USB controller> port 0x1020-0x103f irq 10 at device 
16.0 on pci0
uhci1: [GIANT-LOCKED]
uhub1: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub1: 2 ports with 2 removable, self powered
uhci2: <VIA 83C572 USB controller> port 0x1060-0x107f irq 11 at device 
16.1 on pci0
uhci2: [GIANT-LOCKED]
uhub2: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub2: 2 ports with 2 removable, self powered


Any clues? Where should I look at? I'm concerned with 'USB revision 1.0' 
in the output -- could that be the problem?

-- 
Vlad Skvortsov, vss at 73rus.com, http://vss.73rus.com