These types of tests should be run against the raw device.  You are
proving nothing with this test.

On Mon, Aug 25, 2008 at 06:58:30PM -0700, Neko 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

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