From owner-freebsd-scsi  Sun May 21  5:21:51 2000
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Date: Sun, 21 May 2000 08:21:10 -0400 (EDT)
From: Kenneth W Cochran <kwc@world.std.com>
Message-Id: <200005211221.IAA01609@world.std.com>
To: freebsd-scsi@freebsd.org
Subject: SCSI 2x-4x slower than IDE?
Sender: owner-freebsd-scsi@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.org

Hello -scsi,

(Yes, the old SCSI vs IDE flamewar, but I'd like to avoid that,
thank you...  :)

This is related to FreeBSD because I'm considering these devices
for a FreeBSD box...  :)  A recent message on this list spoke to
this issue in general but I could use some info as to the
specifics, if possible.

Partly on my recommendation, a freind of mine tried SCSI as a
proposed upgrade to his old IDE system.  He is/was interested in
improving performance with sequential saves while editing &
cd-burning music (live recorded recitals).  File sizes are in
the 10s & possibly 100s of mb.

He got a Tekram DC-390U2W & an IBM Ultrastar DNES-318350.  There
are/were a couple of other previous scsi peripherals (older IBM
hdd & a tape drive, I think) running on an Adaptec 2910.  OS is
Win9x (not sure exactly which).

What happened:  Sequential saves with older scsi disk (vs older
ide) took twice as long, & sequential saves with new IBM took
twice as long as with older scsi disk.

The file/save on the ide took about 4 minutes, the "old" scsi
disk (an IBM) took 8 minutes & the new IBM DNES took 15m:21s.
His IDE is not even the newer, supposedly faster, stuff.

I've always read & heard that Unix in general & FreeBSD more
specifically perform much better with scsi hdds than ide
(better, more intelligent i/o, "multithreadedness,"
multitasking, etc.), & that this might not be the case with
Win9x, due to its "single-threaded" nature, but would that
account for this magnitude of performance difference?

I've always been quite satisfied with scsi & unhappy with ide
for systems I've built & used (Unix, Linux, *BSD).  2 questions:

1.  What's going on "here" in M$/Win9x?

2.  What does this imply (or not imply) for FreeBSD?

FAQ, -doc, & other reference pointers are, of course, quite welcome.  :)

Thanks,

-kc


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