*BSD News Article 99100


Return to BSD News archive

Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.ecn.uoknor.edu!news.wildstar.net!newsfeed.direct.ca!news.maxwell.syr.edu!howland.erols.net!newshub2.home.com!newshub1.home.com!news.home.com!news1.best.com!news.idiom.com!not-for-mail
From: karl@idiom.com (Karl)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Using "dd" as a benchmark?
Date: 5 Jul 1997 21:56:19 -0700
Organization: karl@idiom.com
Lines: 32
Message-ID: <5pn8hj$lc0@idiom.com>
NNTP-Posting-Host: idiom.com
Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:44006

For the curious, here's three readings from idiom, which is run on 2.1.7,
one from mine which is 2.2.2, and one from linux Slackware 3.2:

idiom% dd if=/dev/zero of=/dev/null bs=1m count=1000
1000+0 records in
1000+0 records out
1048576000 bytes transferred in 15 secs (69905066 bytes/sec)
idiom% dd if=/dev/zero of=/dev/null bs=1m count=1000
1000+0 records in
1000+0 records out
1048576000 bytes transferred in 34 secs (30840470 bytes/sec)
idiom% dd if=/dev/zero of=/dev/null bs=1m count=1000
1000+0 records in
1000+0 records out
1048576000 bytes transferred in 29 secs (36157793 bytes/sec)
karl% dd if=/dev/zero of=/dev/null bs=1m count=1000
1000+0 records in
1000+0 records out
1048576000 bytes transferred in 11.154818 secs (94002071 bytes/sec)
linux% time dd if=/dev/zero of=/dev/null bs=1048576 count=1000
1000+0 records in
1000+0 records out
0.010u 64.010s 1:04.10 99.8%    0+0k 0+0io 69pf+0w

But what exactly of the memory system does it benchmark?  I have p166,
64 ram and, I think, 128k cache.

If it only measures the cache system, would it also do it for linux,
perhaps?  Even if not, it'd still be useful for making sure you have
enough cache for the ram (AST insists that I have 256k cache, and cannot
be upgraded, in contradiction to what the manual says.)