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Date:      Tue, 26 Jan 1999 22:18:13 -0700 (MST)
From:      "Kenneth D. Merry" <ken@plutotech.com>
To:        roberto@keltia.freenix.fr (Ollivier Robert)
Cc:        freebsd-hardware@FreeBSD.ORG
Subject:   Re: SCSI-3 vrs. ATA
Message-ID:  <199901270518.WAA48800@panzer.plutotech.com>
In-Reply-To: <19990127002442.A78002@keltia.freenix.fr> from Ollivier Robert at "Jan 27, 99 00:24:42 am"

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Ollivier Robert wrote...
> According to David Webster:
> > way get your self a reputable Raid controller and at least three
> > 10,000RPM Ultrawide SCSI drives from someone like Seagate in a Raid5
> 
> Well, we could argue about the 10k rpms drives. Is there so big a
> difference with 7200 rpms ones ? It seems to me that 10k are only slightly
> faster but they're warmer and noisier.

How many 7200 RPM drives can do 18MB/sec?  I've got a machine with two 18GB
Seagate Cheetah II's in a CCD array.  They can do 36MB/sec reads, and 30 or
31MB/sec writes.  The third generation Cheetahs look like they'll be even
faster.  [ NB:  the read rate *could* be a little low, since there is one
other disk on the chain, and unfortunately the SCA->68pin converters we
have seem to force single ended operation.  i.e., we're limited to 20MHz
Wide instead of 40MHz Wide. ]

My IBM Ultrastar 9ZX can do between 13 and 15MB/sec.

For a good comparison, go to the Seagate or IBM web sites, and compare
their latest-generation 7200 RPM drives with their latest-generation 10000
RPM drives.  It looks like for both vendors, their 10K RPM drives are
generally about 5MB/sec faster than their 7200RPM drives.

Ken
-- 
Kenneth Merry
ken@plutotech.com

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