From owner-freebsd-questions Sun Apr 22 10: 8:43 2001 Delivered-To: freebsd-questions@freebsd.org Received: from superconductor.rush.net (superconductor.rush.net [208.9.155.8]) by hub.freebsd.org (Postfix) with ESMTP id ABDB437B423 for ; Sun, 22 Apr 2001 10:08:40 -0700 (PDT) (envelope-from aberrant@superconductor.rush.net) Received: (from aberrant@localhost) by superconductor.rush.net (8.11.2/8.11.2) id f3MH8ck05648; Sun, 22 Apr 2001 13:08:38 -0400 (EDT) Date: Sun, 22 Apr 2001 13:08:38 -0400 From: Seth To: Andrew Hesford Cc: freebsd-questions@freebsd.org Subject: Re: ATA100 read/write perofrmance disparity Message-ID: <20010422130838.B29944@superconductor.rush.net> References: <20010422114836.A6234@superconductor.rush.net> <20010422110843.A99388@cec.wustl.edu> <20010422124619.A29944@superconductor.rush.net> <20010422120120.A26375@cec.wustl.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0us In-Reply-To: <20010422120120.A26375@cec.wustl.edu>; from ajh3@chmod.ath.cx on Sun, Apr 22, 2001 at 12:01:20PM -0500 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sun, Apr 22, 2001 at 12:01:20PM -0500, Andrew Hesford wrote: > During the dd write, your system is being used less than 25% of the > time. This is absolutely horrible. Recall that, for my small-block > write, my CPU was being used >50% of the time, and I had Mozilla > building in the background. This means my CPU usage was much higher. There's nothing else eating up CPU time here. Honestly. I do notice that dd spends a lot of time in the "wdrain" state (when it's not in CPU), according to top(1). I also see brief "bioread" states. I don't know what these states really mean. > Something is definitely wrong. On the I/O writes where you get 6000-7000 > K/sec, I get 9000-13000 K/sec. And mine is a UDMA-4 (UltraATA/66) > controller and drive pair. On the Block I/O, where you get 25000 K/sec, > I get 86000. Hm. This certainly isn't encouraging, although your CPU is much more powerful (and therefore is probably less limiting).. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message