From owner-freebsd-stable@FreeBSD.ORG Mon May 12 06:09:38 2008 Return-Path: Delivered-To: stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 906FF106566C; Mon, 12 May 2008 06:09:38 +0000 (UTC) (envelope-from jdc@parodius.com) Received: from mx01.sc1.parodius.com (mx01.sc1.parodius.com [72.20.106.3]) by mx1.freebsd.org (Postfix) with ESMTP id 7C6E08FC1B; Mon, 12 May 2008 06:09:38 +0000 (UTC) (envelope-from jdc@parodius.com) Received: by mx01.sc1.parodius.com (Postfix, from userid 1000) id 68E721CC033; Sun, 11 May 2008 23:09:38 -0700 (PDT) Date: Sun, 11 May 2008 23:09:38 -0700 From: Jeremy Chadwick To: "Andrey V. Elsukov" Message-ID: <20080512060938.GA2007@eos.sc1.parodius.com> References: <29626.214.13.212.30.1210554531.squirrel@www.kc8onw.net> <20080512030647.GA93725@eos.sc1.parodius.com> <4827D531.7000603@yandex.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4827D531.7000603@yandex.ru> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: stable@freebsd.org, jonathan@kc8onw.net, sos@FreeBSD.org Subject: Re: ATA APM and NCQ support in FreeBSD atacontrol X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 12 May 2008 06:09:38 -0000 On Mon, May 12, 2008 at 09:27:13AM +0400, Andrey V. Elsukov wrote: > Jeremy Chadwick wrote: >> I believe NCQ is supported, assuming that your controller is operating >> in AHCI mode and your disk supports NCQ. This mainly applies to Intel >> ICHx controllers, but there are others which support it as well. >> There's also NCQ support in non-AHCI drivers like hptmv(4), rr232x(4), >> hptrr(4), and mpt(4) with SATA disks. > > No. ata(4) driver currently doesn't support/use NCQ. Thanks for this information -- I had no idea! I'll add this to my Common Issues page, although it's not so much an "issue" but more so a feature. I was always under the impression that AHCI included automatic support for negotiation and use of extensions like NCQ and TCQ: http://en.wikipedia.org/wiki/Native_Command_Queuing http://www.seagate.com/content/docs/pdf/whitepaper/D2c_tech_paper_intc-stx_sata_ncq.pdf -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |