From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262960AbTDFNEa (for ); Sun, 6 Apr 2003 09:04:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262962AbTDFNEa (for ); Sun, 6 Apr 2003 09:04:30 -0400 Received: from siaab1ab.compuserve.com ([149.174.40.2]:4305 "EHLO siaab1ab.compuserve.com") by vger.kernel.org with ESMTP id S262960AbTDFNE2 (for ); Sun, 6 Apr 2003 09:04:28 -0400 Date: Sun, 6 Apr 2003 09:13:18 -0400 From: Chuck Ebbert <76306.1226@compuserve.com> Subject: hdparm -tT reports "suspicious results" ??? To: linux-kernel Message-ID: <200304060915_MC3-1-333E-AEEA@compuserve.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Real-world benchmarks show I am getting about 30-32 MB/sec from my IDE disks on 2.4.21-pre6: raid1 rebuild reports 32MB/sec and copying a 1GB file to /dev/null on a newly-mounted fs takes 33 sec. I have moved the disk to another computer that is almost 100% identical except for CPU (PPro 200 vs. PII ODP/333) and now hdparm says 24MB/sec but I am still getting 30-32 real world on the PPro 200. The below results are from the PII Overdrive (I have not tested real-world on 2.5 but notice how much slower hdparm reports its speed.) What does "suspicious" mean here? # uname -a Linux d2 2.4.21-pre6 #3 Fri Apr 4 18:22:11 EST 2003 i686 unknown # hdparm -tT /dev/hde /dev/hde: Timing buffer-cache reads: 128 MB in 2.50 seconds = 51.20 MB/sec Timing buffered disk reads: 64 MB in 2.15 seconds = 29.77 MB/sec Hmm.. suspicious results: probably not enough free memory for a proper test. # Script done on Fri Apr 4 20:49:01 2003 Script started on Fri Apr 4 20:52:03 2003 # uname -a Linux d2 2.4.20 #1 Fri Apr 4 17:33:07 EST 2003 i686 unknown # hdparm -tT /dev/hde /dev/hde: Timing buffer-cache reads: 128 MB in 2.62 seconds = 48.85 MB/sec Timing buffered disk reads: 64 MB in 2.35 seconds = 27.23 MB/sec Hmm.. suspicious results: probably not enough free memory for a proper test. # Script done on Fri Apr 4 20:52:46 2003 Script started on Fri Apr 4 20:56:54 2003 # uname -a Linux d2 2.5.66 #11 Sat Mar 29 21:14:17 EST 2003 i686 unknown # hdparm -tT /dev/hde /dev/hde: Timing buffer-cache reads: 128 MB in 2.66 seconds = 48.14 MB/sec Timing buffered disk reads: 64 MB in 3.90 seconds = 16.41 MB/sec # cat /proc/meminfo MemTotal: 191956 kB MemFree: 170728 kB Buffers: 4244 kB Cached: 9548 kB SwapCached: 0 kB Active: 7908 kB Inactive: 7764 kB HighTotal: 0 kB HighFree: 0 kB LowTotal: 191956 kB LowFree: 170728 kB SwapTotal: 262040 kB SwapFree: 262040 kB Dirty: 8 kB Writeback: 0 kB Mapped: 3668 kB Slab: 3932 kB Committed_AS: 2616 kB PageTables: 292 kB ReverseMaps: 2832 Configuration (now): Dell Optiplex GXPro (MPS 1.4) 1 PPro 200, Uniprocessor IO-APIC kernel Promise Ultra 100TX2 2 x Maxtor 4K060H3 (60GB 5400RPM) (1 drive per channel) -- Chuck I am not a number!