Re: [Thinkpad] X40 HD/USB very slow?

It's a Samsung drive in an Antec enclosure -- and it's perfectly fast on the
X61s.

I think he was saying that his drive was only serving at 3.5MB/s -- and so
even though he had a potential of ~20MB/s vis USB2, it was limited to
3.5MB/s because of his drive.

I'm not quite sure what to check, but it's definitely *much* slower on the
X20 than the X61s...

Thanks, -Scott

> I remember reading here that the T40 had an early and buggy implementation
> of USB 2.0, so it wouldn't surprise me if the X40 had the same.
>
> However, 3.5MiB/sec is much faster than USB1. USB 2.0 has a theoretical
peak
> speed of 55MiB/sec, but the command overhead in the USB stack and storage
> protocol makes it really closer to 20MiB/sec. Divide that by 40 (the speed
> multiplier from USB1/USB2) and you get 500KiB/sec.
>
> What model of USB drive is it? I'm wondering what the bandwidth of the
> USB/IDE chip used is.
>
> On Nov 14, 2007 7:43 AM, Scott Matthews <scott@turnstyle.com> wrote:
>
> > Hi all, I just plugged a fast USB2 drive into my X40. I've used the same
> > drive on an X61s, and it was perfectly fast. But on the X40, it's very
> > slow.
> >
> > A bit of Googling (http://forum.thinkpads.com/viewtopic.php?t=27910) and
I
> > found somebody with the same problem, and he decided that the bottleneck
> > was
> > his X40 drive -- at about 3.5MB/s (not much faster than USB1) as opposed
> > to
> > about 25MB/s for USB2.
> >
> > Does anybody know if the X40 drive simply can't transfer data at a
> > reasonable speed?
> >
> >
> > _______________________________________________
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> > Thinkpad@stderr.org
> > http://stderr.org/cgi-bin/mailman/listinfo/thinkpad
> >
>
>
>
> --
> - Alex Austin
> Circuitsoft Computer Services
> (651) 238-9273
> www.circuitsoftcs.com
>
> "...and then I visited Wikipedia ...and the next 8 hours are a blur."
>

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Received on Wed Nov 14 09:30:58 2007