Date: Thu, 18 Apr 1996 14:19:00 -0700 From: "Amancio Hasty Jr." <hasty@rah.star-gate.com> To: "Justin T. Gibbs" <gibbs@freefall.freebsd.org> Cc: hackers@freebsd.org Message-ID: <199604182119.OAA04063@rah.star-gate.com>
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Subject: Re: QUEUE_FULL_ENABLE option really work?
In-reply-to: Your message of "Thu, 18 Apr 1996 13:55:26 PDT."
<199604182055.NAA08285@freefall.freebsd.org>
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BTW: Muchas Gracias for the 2940 scsi driver 8) It is working without a hitch
over here after I sorted out my scsi termination problems. Not once
after the driver fixes and the terimantion problems have my system
crashed due to disk failure 8)
Regards,
Amancio
>>> "Justin T. Gibbs" said:
> The option is QUEUE_FULL_SUPPORTED and it does what its supposed to.
> It increases the number of tags allowed per device to 4 instead of
> the default of two.
>
> >I just turned it off on a box with a 2940, and across the board I'm
> >picking up 700-800k/s improvements:
> >
> >old:
> >
> >IOZONE performance measurements:
> > 1168024 bytes/second for writing the file
> > 4445767 bytes/second for reading the file
> >
> >
> >new:
> >
> >IOZONE performance measurements:
> > 1790285 bytes/second for writing the file
> > 5332448 bytes/second for reading the file
>
> But your random I/O scores will decrease since the drive will only
> have at max two I/Os to sort in order to reduce seeks. If you're
> only interested in sequential I/O, you might as well turn off
> tagged queueing since for some devices you will get better results.
>
> --
> Justin T. Gibbs
> ===========================================
> FreeBSD: Turning PCs into workstations
> ===========================================
>
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