From owner-freebsd-chat Sun Jun 17 5:24:45 2001 Delivered-To: freebsd-chat@freebsd.org Received: from guru.mired.org (okc-65-26-235-186.mmcable.com [65.26.235.186]) by hub.freebsd.org (Postfix) with SMTP id DE8CF37B418 for ; Sun, 17 Jun 2001 05:24:31 -0700 (PDT) (envelope-from mwm@mired.org) Received: (qmail 86138 invoked by uid 100); 17 Jun 2001 12:24:24 -0000 From: Mike Meyer MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15148.41335.928818.113165@guru.mired.org> Date: Sun, 17 Jun 2001 07:24:23 -0500 To: Rik van Riel Cc: freebsd-chat@FreeBSD.ORG, freebsd-hackers@FreeBSD.ORG Subject: Re: Article Network performance by OS In-Reply-To: References: <006701c0f6b9$dd6d89e0$3fac6395@alink> X-Mailer: VM 6.90 under 21.1 (patch 14) "Cuyahoga Valley" XEmacs Lucid X-face: "5Mnwy%?j>IIV\)A=):rjWL~NB2aH[}Yq8Z=u~vJ`"(,&SiLvbbz2W`;h9L,Yg`+vb1>RG% *h+%X^n0EZd>TM8_IB;a8F?(Fb"lw'IgCoyM.[Lg#r\ Sender: owner-freebsd-chat@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Rik van Riel types: > On Sat, 16 Jun 2001, Jonathan Fortin wrote: > > Linux is tuned out of the box, where the others are tuned for > > stability. > Not quite. Linux distributions tend to be extremely > conservative in the IDE options (DMA, interrupt unmasking, > write caching, etc. all disabled) while FreeBSD seems to > have write caching and DMA on by default... This doesn't agree with what was said about IDE write cache in Linux when it was toggled in FBSD. At that point, it was claimed that 1) Linux left the disk write cache in whatever state it found it in, and 2) most drives shipped with write cache enabled, just so they would peform well on benchmarks. In other words - it's generally on by default. On the other hand, all those other options can make a *lot* of difference. I've got some old tests I ran on 3.x wd driver with a brand new disk. Here's what bonnie says for one test with none of the go-fast options on: -------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 wd 100 2300 14.2 2285 6.7 1350 6.0 2499 17.7 2729 6.5 123.4 3.2 And here's what it says when you turn on UDMA and all those good things: -------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 wd 100 16841 88.5 15186 26.1 16610 38.2 21409 100.0 133543 100.0 3004.7 48.6 http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message