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Date: Fri, 15 Aug 1997 15:20:50 +0400 (MSD)
Organization: Landau Institute for Theoretical Physics
From: "Sergey S. Kosyakov" <ks@itp.ac.ru>
To: freebsd-hardware@freebsd.org
Subject: Barracuda speed anomaly
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Hi!

I found very strange Seagate 4Gb & 9Gb disks speed behavio when
tested with iozone and bonnie (FreeBSD-2.2.2) - 9Gb disk two times slower on 
writing in compare with 4Gb disk.

Specification:
AMD K6/233 box with Adaptec AIC7880 Ultra Wide SCSI

ST-34371N Ultra-SCSI (Barracuda 4LP) 4.35Gb, 
          external transfer rate 20 MB/sec Sync,
          internal transfer rate 80 - 122 Mbit/sec
ST-19171N Ultra-SCSI (Barracuda 9)   9.1 Gb, 
          external transfer rate 20 MB/sec Sync,
          internal transfer rate 80 - 124 Mbit/sec

The 9GB disk was divided on two equal volume partitions.

iozone auto
bonnie

Results (appr.):
                  writing                reading
Barracuda 4LP     9 MB/sec           40 MB/sec(iozone) - 10 MB/sec(bonnie)
Barracuda 9       4.5 MB/sec(!)      40 MB/sec - 10 MB/sec

Is it FreeBSD (SCSI driver, file system, etc), Adaptec or Seagate problem ?

----------------------------------
Sergey Kosyakov
Landau Institute for Theoretical Physics
E-Mail: Sergey S. Kosyakov <ks@itp.ac.ru>
Date: 15-Aug-97
Time: 15:20:51
----------------------------------