Date: Sat, 18 Apr 1998 09:45:53 -0700 From: Mike Smith <mike@smith.net.au> To: Mark Mayo <mark@vmunix.com> Cc: stable@FreeBSD.ORG, hardware@FreeBSD.ORG Subject: Re: best wdc0 flags ? Message-ID: <199804181645.JAA04953@antipodes.cdrom.com> In-Reply-To: Your message of "Sat, 18 Apr 1998 02:33:07 EDT." <19980418023307.34709@vmunix.com>
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> Hi. I just put a shiney new IDE (Ultra33) drive in a machine, and
> I'm wondering what the best flags to use for the drive are.. I realize
> that I can't get DMA on -STABLE (cvsupping right now), but with the
> default LINT flags of:
>
> controller wdc0 at isa? port "IO_WD1" bio irq 14 flags 0x00ff8004 ..
> which turns on 32-bit transfers and multi-block-4
I'd generally use 0x80ff80ff and let the autodetection code sort it out
- in fact, I haven't run into a drive/controller combination yet that
doesn't get that right. (Not saying they don't exist, just that the
vast majority of hardware works as desired).
> I'm gettting really crappy performance..
>
> vnode:{76}~ % iozone 160 32000
> ....
> IOZONE performance measurements:
> 2237052 bytes/second for writing the file
> 2264181 bytes/second for reading the file
>
> Now that is horrible. :-) Same results with block-size of 8K.
> I think I'll try without the flag option at all and see how it performs.
>
> Any recomendations appreciated,
> -Mark
>
> P.S. The drive is a Quantum Fireball SE 4.3GB, FWIW.
We've been duplicating 3GB Western Digital disks the last few days under
2.2.6, flags 0x80ff80ff on 166MHz P5/430TX boards, and averaging about
5M/sec throughput. Try 'dd if=/dev/wd1 of=/dev/null bs=1m' to get an
idea of your raw disk speed as opposed to filesystem throughput.
--
\\ Sometimes you're ahead, \\ Mike Smith
\\ sometimes you're behind. \\ mike@smith.net.au
\\ The race is long, and in the \\ msmith@freebsd.org
\\ end it's only with yourself. \\ msmith@cdrom.com
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