Date: Thu, 9 Nov 1995 00:30:51 +0100 From: se@zpr.uni-koeln.de (Stefan Esser) To: faulkner@mpd.tandem.com (Boyd Faulkner) Cc: current@freebsd.org Subject: Re: iozone and mount -o async Message-ID: <199511082330.AA11902@Sysiphos> In-Reply-To: faulkner@mpd.tandem.com (Boyd Faulkner) "iozone and mount -o async" (Nov 8, 16:12)
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On Nov 8, 16:12, Boyd Faulkner wrote: } Subject: iozone and mount -o async } With my Maxtor 235M SCSI 1 drive mounted normally } } iozone 32 gives } IOZONE performance measurements: } 804903 bytes/second for writing the file } 1112974 bytes/second for reading the file } } mounted with -o async } IOZONE performance measurements: } 714042 bytes/second for writing the file } 1115575 bytes/second for reading the file I'm seeing slower writes, too, and surprisingly by about the same absolute amount (some 100KB/s). My "iozone 32" results are: se@x14> tail -3 /tmp/sync.io IOZONE performance measurements: 2529427 bytes/second for writing the file 4446135 bytes/second for reading the file se@x14> tail -3 /tmp/async.io IOZONE performance measurements: 2422429 bytes/second for writing the file 4423241 bytes/second for reading the file Bonnie gives significantly different results, too: -------Sequential Output-------- ---Sequential Input-- --Random-- -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks--- Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU sync 100 1505 98.6 3267 31.2 2167 42.3 1656 98.5 5929 72.1 78.4 9.2 async 100 1425 96.4 2661 24.3 2077 41.7 1644 98.0 5923 72.1 78.9 9.1 All tests on the half ful inner (slower) half of my 2GB Atlas driven by an ASUS SP3G, 486DX2/66, NCR SCSI. Regards, STefan -- Stefan Esser, Zentrum fuer Paralleles Rechnen Tel: +49 221 4706021 Universitaet zu Koeln, Weyertal 80, 50931 Koeln FAX: +49 221 4705160 ============================================================================== http://www.zpr.uni-koeln.de/~se <se@ZPR.Uni-Koeln.DE>
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