From owner-freebsd-drivers@FreeBSD.ORG Mon May 17 21:51:11 2010 Return-Path: Delivered-To: freebsd-drivers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E5232106566C for ; Mon, 17 May 2010 21:51:11 +0000 (UTC) (envelope-from dieterbsd@engineer.com) Received: from imr-ma04.mx.aol.com (imr-ma04.mx.aol.com [64.12.206.42]) by mx1.freebsd.org (Postfix) with ESMTP id A67C08FC08 for ; Mon, 17 May 2010 21:51:11 +0000 (UTC) Received: from imo-da04.mx.aol.com (imo-da04.mx.aol.com [205.188.169.202]) by imr-ma04.mx.aol.com (8.14.1/8.14.1) with ESMTP id o4HLf5le026929 for ; Mon, 17 May 2010 17:41:05 -0400 Received: from dieterbsd@engineer.com by imo-da04.mx.aol.com (mail_out_v42.9.) id n.df0.6a75e30 (43999) for ; Mon, 17 May 2010 17:41:04 -0400 (EDT) Received: from smtprly-me02.mx.aol.com (smtprly-me02.mx.aol.com [64.12.95.103]) by cia-dd06.mx.aol.com (v129.4) with ESMTP id MAILCIADD068-b2ca4bf1b7e337c; Mon, 17 May 2010 17:41:04 -0400 Received: from web-mmc-m09 (web-mmc-m09.sim.aol.com [64.12.224.142]) by smtprly-me02.mx.aol.com (v129.4) with ESMTP id MAILSMTPRLYME024-b2ca4bf1b7e337c; Mon, 17 May 2010 17:40:51 -0400 To: freebsd-drivers@freebsd.org Content-Transfer-Encoding: quoted-printable Date: Mon, 17 May 2010 17:40:51 -0400 X-MB-Message-Source: WebUI X-AOL-IP: 72.251.79.159 X-MB-Message-Type: User MIME-Version: 1.0 From: dieterbsd@engineer.com Content-Type: text/plain; charset="us-ascii"; format=flowed X-Mailer: Mail.com Webmail 31650-STANDARD Received: from 72.251.79.159 by web-mmc-m09.sysops.aol.com (64.12.224.142) with HTTP (WebMailUI); Mon, 17 May 2010 17:40:51 -0400 Message-Id: <8CCC420C1490C4B-1B6C-360B@web-mmc-m09.sysops.aol.com> X-Spam-Flag: NO X-AOL-SENDER: dieterbsd@engineer.com Subject: NCQ for nforce4-ultra? X-BeenThere: freebsd-drivers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Writing device drivers for FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 17 May 2010 21:51:12 -0000 FreeBSD 8.0 amd64 FFS w/softdeps Performance writing a single file: device r/s w/s kr/s kw/s wait svc_t %b ada5 2.5 728.0 40.0 93184.1 7 5.5 76 Copy 4 files from 4 disks to one disk, to test write performance when seeking: device r/s w/s kr/s kw/s wait svc_t %b ada5 2.0 556.4 32.0 71213.9 44 114.1 100 NCQ is helping even more than I expected. Without NCQ, write speed runs only 6-7 MB/s writing a single file (minimal seeking). I don't want to think about how slow it would be trying to write multiple files at once. Plus, writing to a non-NCQ disk affects unrelated processes accessing other disks. My theory is that the buffer cache gets clogged up. This destroys the performance of the entire system. Processes hang for tens of minutes. Unfortunately, neither achi(4) nor siis(4) support the nforce4-ultra chipset. Is there a driver I can load to get NCQ with the=20 nforce4-ultra?