Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751162AbYGDEgA (ORCPT ); Fri, 4 Jul 2008 00:36:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751095AbYGDEfu (ORCPT ); Fri, 4 Jul 2008 00:35:50 -0400 Received: from idcmail-mo1so.shaw.ca ([24.71.223.10]:24959 "EHLO pd2mo3so.prod.shaw.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750911AbYGDEft (ORCPT ); Fri, 4 Jul 2008 00:35:49 -0400 Date: Thu, 03 Jul 2008 22:35:43 -0600 From: Robert Hancock Subject: Re: Veliciraptor HDD 3.0gbps but UDMA/100 on PCI-e controller? In-reply-to: To: Justin Piszcz Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org Message-id: <486DA89F.9010505@shaw.ca> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit References: User-Agent: Thunderbird 2.0.0.14 (Windows/20080421) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1700 Lines: 42 Justin Piszcz wrote: > On the motherboard itself (all drives configured for AHCI) > > [ 2.360648] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300) > [ 2.678244] ata1.00: ATA-8: WDC WD3000GLFS-01F8U0, 03.03V01, max > UDMA/133 > [ 2.678594] ata1.00: 586072368 sectors, multi 0: LBA48 NCQ (depth 31/32) > [ 2.684566] ata1.00: configured for UDMA/133 > > On the PCI-e cards: > > [ 16.136568] ata11: SATA link up 3.0 Gbps (SStatus 123 SControl 0) > [ 16.155682] ata11.00: ATA-8: WDC WD3000GLFS-01F8U0, 03.03V01, max > UDMA/133 > [ 16.156545] ata11.00: 586072368 sectors, multi 16: LBA48 NCQ (depth > 31/32) > [ 16.162949] ata11.00: configured for UDMA/100 > > How come the PCI-e card configured the drive for UDMA/100 and not UDMA/133? > > Perhaps the PCI-e card/driver does not configure/have AHCI > functionality, or? > > The mobo: Intel DG965WH > The card: 03:00.0 RAID bus controller: Silicon Image, Inc. SiI 3132 > Serial ATA Raid II Controller (rev 01) > > The hard drives are the same make/model. Not sure exactly why that is (could be an artificial driver difference), but for SATA I don't think the UDMA mode selection matters at all as far as throughput. SATA uses its own flow control mechanism, and the UDMA rate has no real meaning. And no, the card is not AHCI, it's Silicon Image's own interface, which has most of the same features. (I'm not aware of any AHCI add-in cards, though they may exist..) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/