[GRLUG] External drive transfer rates

[Bob Kline]

On 10/20/07, Michael Mol <mikemol at gmail.com> wrote:
>
> On 10/20/07, Bob Kline <bob.kline at gmail.com> wrote:
> > On 10/20/07, Bob Kline <bob.kline at gmail.com> wrote:
> > > On 10/20/07, Michael Mol < mikemol at gmail.com> wrote:
>
> [snipped]
>
> > > > How about:
> > > >
> > > > mount -t ext3 -o async  /dev/X  /disk2
> > >
> > >
> > >
> > > That would seem to make sense, but the
> > > man page for mount suggests that the
> > > default is async.
> > >
> > > One can use
> > >
> > > mount -t ext3  -o defaults /dev/X  /disk2
> > >
> > > but its unclear why this is useful.  I'm
> > > assuming that one doesn't need it, but
> > > will try it just to be sure.
> > >
> > > More later.
>
> [snipped]
>
> >
> > The async option is apparently the default,
> > and has no affect on the slow transfer rates
> > I'm seeing.
> >
> > Some have wondered whether the connection
> > is somehow defaulting to a USB 1.1 mode.  But
> > if so, I see no way to do anything about that.
>
> What kind of performance do you get if you try:
>
> dd if=/dev/X of=/dev/null bs=1M count=1000
>
>


On the Mandriva machine it took 231 seconds,
for a bit rate of 4.5 MBps,  or 36 Mbps.  That's
about 50% faster than the mounted transfer
rate using cp.

I'll check the Kubuntu machine after I finish doing
something else.

    -Bob
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