Abysmal performance on external usb drive
Dread Pirate Mal
dreadpirate at gmail.com
Fri Jan 13 12:34:39 PST 2006
Hi, folks.
I'm seeing -really- terrible performance with an external usb drive on
my freebsd 5.4 machine. It's a matrox one-touch being attached as the only
device on port 0 of an Intel S845W<mumble> based system. And yes, I do have
ehci compiled in and the most current bios for the board :).
I'd like to buy a vowel please, and apologies for the spammage.
--------------------------------------------------------------------------------
Dmesg sez the following:
uhci0: <Intel 82801BA/BAM (ICH2) USB controller USB-A> port 0xef40-0xef5f
irq 1\
9 at device 31.2 on pci0
usb0: <Intel 82801BA/BAM (ICH2) USB controller USB-A> on uhci0
usb0: USB revision 1.0
uhub0: Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 2 ports with 2 removable, self powered
umass0: Maxtor OneTouch II, rev 2.00/2.03, addr 2
umass0: Get Max Lun not supported (STALLED)
da0: <Maxtor OneTouch II 023d> Fixed Direct Access SCSI-4 device
da0: 1.000MB/s transfers
da0: 194481MB (398297088 512 byte sectors: 255H 63S/T 24792C)
--
Rough i/o test sez:
dd if=/dev/da0s1c bs=16k count=10000 of=/dev/null yields:
163840000 bytes transferred in 191.111406 secs (857301 bytes/sec)
--
And.. oh, the pain:
diskinfo -tv /dev/da0s1c
/dev/da0s1c
512 # sectorsize
203921109504 # mediasize in bytes (190G)
398283417 # mediasize in sectors
24791 # Cylinders according to firmware.
255 # Heads according to firmware.
63 # Sectors according to firmware.
Seek times:
Full stroke: 250 iter in 13.312930 sec = 53.252 msec
Half stroke: 250 iter in 4.936923 sec = 19.748 msec
Quarter stroke: 500 iter in 8.466121 sec = 16.932 msec
Short forward: 400 iter in 3.550715 sec = 8.877 msec
Short backward: 400 iter in 3.516539 sec = 8.791 msec
Seq outer: 2048 iter in 10.288395 sec = 5.024 msec
Seq inner: 2048 iter in 10.269045 sec = 5.014 msec
Transfer rates:
outside: 102400 kbytes in 98.968530 sec = 1035 kbytes/sec
middle: 102400 kbytes in 99.359594 sec = 1031 kbytes/sec
inside: 102400 kbytes in 98.932885 sec = 1035 kbytes/sec
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