> From: Ted Unangst <ted.unangst@gmail.com>
> Subject: Re: dd performance question
> To:
fur3fur3@yahoo.com
> Cc:
misc@openbsd.org
> Date: Monday, August 25, 2008, 11:26 PM
> I'm going to ask the obvious question. Why are you
> trying to do
> whatever it is you're trying to do the hardest way
> possible?
>
> On Mon, Aug 25, 2008 at 9:58 PM, Neko
> <fur3fur3@yahoo.com> wrote:
> > Hi all,
> >
> > having a 250 GB drive on a PATA strip using lowest PIO
> mode (without dma if possible), drive specs show a 8 MB
> buffer ,
> >
> > 2 cases are : on same pata strip, one on each strip,
> >
> > important to note that the booted drive is the
> if's straight up to my slave.
> > (yea i know ill have to run fsck afterwards since itll
> think it still mounted)
> > and having no user but su himself.
> >
> > i had ran mine at 4mb block space thinking ill use the
> 16mb bus transfer
> > divided at most in 4, per second, but i achieved that
> in a minute instead.
> > this is really poor performance, 3 days for 250gb
> transfer at 4mb bs
> >
> > dd if=/dev/wd0c of=/dev/wd1c bs=4m
> >
> > so what if i was to use
> >
> > dd if=/dev/wd0c of=/dev/wd1c bs=4000m
> >
> > or more, or reflecting number sector divided by lets
> say 16... would in
> > the end i get the same effect, what are the plateau i
> should top of,
> > a mb is way too cheezy
> >
> > i have 512mb of ram, would 512mb be the most ? the
> machine is idling either way.
> >
> >
> > neko
