USB-Speed slows down with 3.9

[frakes]

Hi,

i use Knoppix 3.9 and an external Fujitsu 2,5" HD 40GB in an USB-Case.

I want to use partimage to make an uncompressed disk image and want to save the image on the external HD. Storing starts with round about 50MB/m and slows down to 10MB/m within 5 minutes.

What could be the reason therefor?

cu, Frakes

[tinaerwin]

care if you have:
not a frontpanel connector with unshielded cable to the mainboard - use the usb ports on the back directly on the mainboard
use a shielded usb2 cable for outside the computer - never use a wire with some plastic on it as many cheap cardreaders!
if this still doesnt work, try out another pc, maybe your controller is defective, socket .. damaged
touch the computer first, then plug in usb device (static discharge)
good luck

[frakes]

Hi,

i use the usb-ports on the motherboard with a standard usb-cable. I tried another PC to write back the image and it was the same, first 60MB/min then it slows down to 15MB/min.

The case, the HD and the cable are OK, i tried them on the same PC's under W2K-Professional and it works fast. It has to be an error on the combination external HD and Knoppix.

cu, Frakes

[tinaerwin]

i reached ~18MB/s (i used a clock for measuring time) with knoppix 3.7 2004-08-16 (cheatcode ... usb2)
ill hav a try on win2000 for to see the max. of my usb-hdd -
usb2 max would be ~40MB/s - a usb2.0-hdd reaches far below

v3.9 wont reach more than ~3MB/s !?!
do you use any cheatcodes?

on my ancient pc166 usb1.1 only 0.5MB/s no matter which knoppix

[frakes]

Hi,

i'll check it out the day after tomorrow. i'm meanwhile unsure about my average performance with w2kprof.

There were to many numbers after 10 hours of work.


cu, Frakes

[tinaerwin]

i couted the seconds and the maximum write speed
with my chiligreen usb2.0-hdd with a seagate80GB inside on winXP is:

14 MB/s

even worse

[frakes]

Hi,

it's a problem of Knoppix.

I didn't check the average performance, but i took a try with the SystemRescueCD on the same configuration.

It tooks 75 minutes to write compressed 1,5GB to the USB-HD and it take 35 minutes to write the image back on a PC.

It may be a problem with the external USB-HD, or a problem of reading and writing NTFS under Knoppix, or something else.

However, i have to compensate the lost time and can't have a closer look on the problem, i'll check it, if anything runs.

cu, Frakes