On Mon, 31 Mar 1997, Soren S. Jorvang wrote:

> > This strikes me as a bit odd; on my machines (486s, Pentiums,
> > low-end Sparcs) with the standard 8K/1K block/fragment sizes, I
> > normally get very similar speeds out of bonnie and iozone very
> > close to what I get from dd if=/dev/rsdxx of=/dev/null.
> 
> Using what block size for dd? On the system I am writing this on,
> the above 'dd' reads 0.6MB/sec from disk, while 'dd bs=64k' reads 7.1MB/sec
> from the same disk.

Oh, usually 8K or so. My nicer P90 with 7200 RPM disks (Quantum
Atlas) on a Buslogic controller gets about 6 MB/sec on the above
tests.

> I am running -current. Before the MAXPHYS changes, my results were
> pretty much the same as yours.

Hmm. I should think we need to have yet another look at the MAXPHYS
stuff, then, if it's killing performance unless we increase our
block sizes unreasonably. (Moving from 1K to 8K fragments on my
development volume, for example, would waste about 90 MB of disk
space.)

cjs

Curt Sampson    cjs@portal.ca		Info at http://www.portal.ca/
Internet Portal Services, Inc.		`And malt does more than Milton can
Vancouver, BC   (604) 257-9400		 To justify God's ways to man.'