[CentOS] USB 2 card
wpilorz at bdk.pl
Mon Mar 5 23:27:49 UTC 2007
On Mon, 5 Mar 2007, Jamie Lists wrote:
> Date: Mon, 5 Mar 2007 11:21:35 -0800
> From: Jamie Lists <jamielist at gmail.com>
> Reply-To: CentOS mailing list <centos at centos.org>
> To: centos at centos.org
> Subject: [CentOS] USB 2 card
> Were looking to hook up a Lacie 2TB external drive to be our little
> rdiff-backup volume and we need a usb 2 interface.
> Can anyone make a suggestion to a good USB2 PCI card for centos?
I tried to add usb 2.0 card to my old, PIII, i440BX system.
[which is Fedora Core 6 rather then Centos, but I do not think this could make
any difference here. If you want, I could test with Centos 4.4 Live CD,
or install Centos 4.4]
My first try was an EDIMAX card with VIA6212L chip. I wasn't able
to get it to work as USB 2.0 acceptably with any sane meaning of
'acceptable' on my system.
With the VIA based card I could work only with USB 1.1, using USB 2.0
produced immediately lots of messages like that
reset high speed USB device
sd 0:0:0:0: SCSI error: return code = YYYYYY
end_request: I/O error, dev sda, sector ZZZZZ
Buffer I/O error on device sda, logical block XXXX
and of course card was useless.
Then I searched Google, and saw some comments that one should avoid Via
and Ali chips, and use NEC-based cards.
I bought i-tec USB card, and it worked flawlessly (at least with separate
IRQ for EHCI, I disabled Parallel port in BIOS, which I did not need, so
that EHCI got IRQ 7; I did that when trying to get via card with VIA
The card is described (in Polish) at
and (in Czech) at
According to the description the chip is NEC D720100 or D720101.
I have moved several hundreds of GB with that card using external
USB/ATAPI converter and ATAPI hard disk (and a few GB with external USB DVD/RW
drive) and had no problems.
The transfer rate for hard disk I got was 15-20 MB/s, while identical internal disk with
ATA/100 interface get 25-30 MB/s.
I read that 20 MB/s is close to maximal data rate one can get in USB/2
(that 480 Mbit/s seems to be a rather misleading advertising ).
You need to assess, whether about 20MB/s will be enough for your needs.
You could get some faster datarates with FireWire, but I have no experiences
[NOTE. It is quite possible, that VIA card would work better on system with more
current PCI implementation; dmesg on my systems says
PCI: PCI BIOS revision 2.10 entry at 0xfb520, last bus=1
which, I can guess, would mean it is PCI 2.1 rather then 2.2
Could you possibly share with us your experiences?
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