From owner-freebsd-questions Fri Aug 10 0:52: 8 2001 Delivered-To: freebsd-questions@freebsd.org Received: from elvis.mu.org (elvis.mu.org [216.33.66.196]) by hub.freebsd.org (Postfix) with ESMTP id 8CEB037B401 for ; Fri, 10 Aug 2001 00:52:06 -0700 (PDT) (envelope-from bright@elvis.mu.org) Received: by elvis.mu.org (Postfix, from userid 1192) id 7AFEA81D01; Fri, 10 Aug 2001 02:51:56 -0500 (CDT) Date: Fri, 10 Aug 2001 02:51:56 -0500 From: Alfred Perlstein To: Kevin Hui - DCS Cc: freebsd-questions@freebsd.org Subject: Re: Experiencing very slow raw write speeds on /dev/ad1 Message-ID: <20010810025156.N85642@elvis.mu.org> References: <20010809190350.M85642@elvis.mu.org> <007001c12158$b2ee87e0$07010101@mtwx1.on.home.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <007001c12158$b2ee87e0$07010101@mtwx1.on.home.com>; from khui@cs.toronto.edu on Fri, Aug 10, 2001 at 12:55:36AM -0400 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG * Kevin Hui - DCS [010809 23:54] wrote: > Thank you, Alfred, for the hint. word. :) > > Adding write caching helped a lot. Now the write speed jumps to ~15.8MB/s > instead of the previous 3.5MB/s. > Are there any other such settings I should pay attention to? I asked > because I believe that the performance is still not as good as can be. I > have the rawio program running under Linux with the identical hardware > (accessing the /dev/raw/raw0, which maps to /dev/hdb) and I got ~38.4MB/s > raw write speed (BTW I get ~38.4MB/s from both Linux and FreeBSD when I do > the single-process raw sequential read test). I'm a bit confused, where do the numbers differ and what are the numbers? -Alfred To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message