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william

USB 2.0

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I purchased an USB PCI card with 4 ports and the installation was quite easy and simple. I'm running MDK 10 and I was told that the 2.6 kernel had support to the USB 2.0, despite of the fact that the system recognised the USB pci card, I've noticed some improvement in the speed between my USB Iomega drive and the computer, but not sure if it's an impression or the speed has really improved, so here go 2 questions:

 

1 ) How to check if the speed between the computer and USB 2.0 devices is reaching USB 2.0 standards?

2 ) Do I have to enable USB 2.0 module into the 2.6 kernel to feel any improvement?

 

Thanks for the inputs.

Edited by william

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i'm not sure what a USB Iomega drive is, but assuming its a hard drive, just time how long a big file takes to get from the drive to your ide hard drive.

USB 1.1 has a limit of 12Mb/s (i think)

USB 2 has a limit (in theory) of 480 Mb/s

 

you should be able to tell the difference ;-)

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Actually, It's a 750Mb Zip Drive, I will time how long it takes, but is it necessary to compile the kernel in order to make it work properly or just plugging the 2.0 usb devices is enough?

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The kernel should have this support automatically.

 

Read my review, there are some problems due to supermount, you may want to switch that off.

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thank you aRTee. I had been there already (was already bookmarked), but completely forgot that you had writen something on USB 2.0 support.

BTW, congratulations for you good review, very helpful and well writen.

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Zip drives are usually designated sda4 IIRC. You can check the speed using hdparm. Place a zip disk in the drive, open a console, su to root and run:

 

# hdparm -tT /dev/sda

 

For my usb hard drive there is a noticeable speed improvement with the mdk 2.6 kernel as measured by hdparm. In mdk9.2 using the 2.4 kernel I would get transfer rates of around 20MB/sec but in mdk10 using the 2.6 kernel I get around 30MB/sec.

Edited by pmpatrick

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usb support for me in mandrake 10.0 && 9.2 for that matter, is that it doesn't work well with my sandisk usb 2.0 flash drive. When I plug it in, an icon appears on the desktop, but when I try to open it, I get an error. Either that, or it will hang. Also, my usb webcam doesn't work. Hopefully this will get fixed in the full version of 10.0.

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Don't forget to use Mandrake Update and get all your bugfixes and normal updates. I went through the first mirror in France, even though I am in the USA and got well over 500 MB of updates (first update since install). It didn't find any security updates. Strange.

 

Broadband is SO nice for updates.

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pmpatrick, I will check with hdparm and put the output here, considering that Sarissi is correct, ZIP 750 is a USB 2.0 device, so the rates should be a little better.

SurfahBoy, yesterday I had to get some jpg file that was stored in my flash memory card, which is also an USB 2.0 device, and it takes an eternity to copy 10mb to my computer, I had to gave up and today I will try to figure out what happened.

aRTee, I tried you trick of inserting noauto instead supermount, but is it applicable to devices likes memory cards besides HD?

Notice that I'm attaching the devices directly to the USB 2.0 card, no 1.1 hubs.

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USB 2.0 is backward compatible with USB 1.1. See if the EHCI driver is loaded (2.0). OHCI and UHCI are 1.1. It seems like your card reader is being seen as a 1.1 device. You may need to be sure your acpi=off noapic is in the boot loader and be sure to remove acpi=ht from the same line if it is there. I had to do this to get USB working. I don't have any 2.0 devices at this time, though that will change shortly.

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this is the output of hdparm for sda (usb zip drive):

[root@poseidon home]# hdparm -tT /dev/sda  

/dev/sda:
Timing buffer-cache reads:   1044 MB in  2.00 seconds = 521.30 MB/sec

it should be wrong, 521Mb per sec?!!?!?

Sarissi, I don't have acpi service enable, so I presume that during booting time it's not an issue.

Actually, I will spend some time with the memory card, it's not reasonable to wait for a long time to have 12Mb or whaterver copied to my computer.

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That's the disk cache transfer rate. Try running:

 

# hdparm -t /dev/sda

 

The -T is for disk cache and the -t is for disk reads. Here's my output by way of example:

 

# hdparm -Tt /dev/sda

/dev/sda:
Timing buffer-cache reads:   1544 MB in  2.00 seconds = 770.58 MB/sec
Timing buffered disk reads:   92 MB in  3.07 seconds =  30.01 MB/sec

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[root@poseidon william]# hdparm -Tt /dev/sda

/dev/sda:
Timing buffer-cache reads:   1148 MB in  2.00 seconds = 572.94 MB/sec
Timing buffered disk reads:    8 MB in  3.40 seconds =   2.35 MB/sec

 

2.35 MB per sec against your 30 MB per sec, means to say that USB 2.0 is not enabled here. isn't it?

If I'm correct, what am I expected to do?

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USB 1.x is limited to 1.5MB/sec AFAIK so I would guess that USB2.0 is loaded on your system. You can quickly check by opening a console, su to root an running:

 

# lsmod

 

the ehci module should be listed if USB 2.0 is working.

 

This could be a problem with the automounting feature for usb devices which I never use on my external hard drive. I've been told that the automounter reduces transfer speeds because of the constant polling activity built into the automount feature. Post your fstab entry for the zip drive. Maybe we can edit it to get rid of the automounting feature and improve performance.

 

Edit: One further complication. lsmod is included in pciutils which is not installed by default in mdk10-CE. If you get a command not found when trying to run lsmod, install pciutils by running:

 

# urpmi pciutils

 

then run lsmod.

Edited by pmpatrick

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