Subject: Re: Massive read/write performance problems with 3.0
To: Manuel Bouyer <bouyer@antioche.eu.org>
From: Tonnerre LOMBARD <tonnerre@bsdprojects.net>
List: port-amd64
Date: 05/09/2006 23:36:51
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Salut,

On Tue, May 09, 2006 at 12:06:42PM +0200, Manuel Bouyer wrote:
> > I added the O_SYNC parameter to your open() and it sanitized the output
> > quite a bit:
>=20
> As the tool is using the raw device it shouldn't matter. What problem did
> you notice ?

The read speed was around 4000MB/s, which was unreasonable.

> BTW, you could also try to benchmark raw write speed: boot single user and
> use:
> dd if=3D/dev/zero of=3D/dev/rwd0b bs=3D64k (assuming your swap partition =
is wd0b)

There appears to be a significant problem in write speed:

vic# dd if=3D/dev/zero of=3D/dev/rwd0b bs=3D64k count=3D1536
100663296 bytes transferred in 41.410 secs (2430893 bytes/sec)
vic#=20

				Tonnerre

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