USB drive : Speed puzzle

[Groffo]

I'm looking for clues to solve a copy-speed problem.

Copying from my USB dirve I get a transfer speed of approx 1MB/sec. But copying to the drive I get a crippling 30KB/sec! (It takes about 3 minutes to copy a 4MB file to the drive!)

I've tried two different drives now with similar results in Linux. The same gear booted into that other operating system works fine both ways so it's not a hardware problem.

I'm a fairly savvy Linux user but I don't know where to look here.

(FC4 by the way and kernel 2.6.12-1.1378)

[Elv13]

1. can you use firewire?
2. what kind of format system do you use (FAT32?)
3. what is the HDD (RPM model years etc)

[Groffo]

1. can you use firewire?
2. what kind of format system do you use (FAT32?)
3. what is the HDD (RPM model years etc)

1: No, can't use firewire.

2: Both USB drives are FAT32. (I see where you're going with this! I've just tried copying from the USB to a FAT32 HDD partition but the results are similar - 978KB/s from USB and 32KB/s to USB.)

3: The HDD's a 40 GB Seagate ST340016A, 7200 rpm, 9 ms avg seek

[Elv13]

usb 1.1 or 2.0?
and what speed do you get if you install the kernel from source at kernel.org?

[Groffo]

usb 1.1 or 2.0?
and what speed do you get if you install the kernel from source at kernel.org?

Both devices are USB 2.0.

Rather than spend the afternoon building kernels I re-booted the machine into Mandrake 10 (it's dual boot Linux) and tried the USB drive there. I get 760KB/s from USB and 711KB/s to USB so it's clearly a kernel problem. But what should I be tweaking when I rebuild the kernel?

[Elv13]

look at your mandrake kernel

[steve941]

do yum update/ get updated kernel.. what tools do you use to calculate speed? ... 1MB/s is slow ... what computer do you have, are you using a USB 2.0 slot / compliant motherboard?