From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: Question with AHCI and (UDMA/100 vs. UDMA/133) Date: Wed, 31 Dec 2008 14:40:59 +0300 Message-ID: <495B5A4B.5030205@ru.mvista.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from homer.mvista.com ([63.81.120.155]:40492 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1756089AbYLaLlH (ORCPT ); Wed, 31 Dec 2008 06:41:07 -0500 In-Reply-To: Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Justin Piszcz Cc: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org Hello. Justin Piszcz wrote: > Do some chipsets (SiI 3132 vs. Intel ICH9) run certain drives at > UDMA/100 vs. UDMA/133? Intel ICH chipsets never supported UDMA/133. > I have several 750GB WD drives (exact make/model) and the ones on the > intel chipset show up as: > > [ 1.407321] ata3.00: ATA-7: WDC WD7500AAKS-00RBA0, 30.04G30, max > UDMA/133 > [ 1.407409] ata3.00: 1465149168 sectors, multi 0: LBA48 NCQ (depth > 31/32) > [ 1.408300] ata3.00: configured for UDMA/133 I'm *very* surprised to see that on ICH9. Oh wait, that's SATA controller, not PATA! Then I don't know... > The ones on the SiI 3132 chipset show up as: > > [ 9.604413] ata11: SATA link up 3.0 Gbps (SStatus 123 SControl 0) > [ 9.619024] ata11.00: ATA-7: WDC WD7500AAKS-00RBA0, 30.04G30, max > UDMA/133 > [ 9.619111] ata11.00: 1465149168 sectors, multi 16: LBA48 NCQ > (depth 31/32) > [ 9.620029] ata11.00: configured for UDMA/100 > > If they are both 3.0 Gbps, are they both the same speed even though > one is configured for a slower speed than the other? I'd think so. > Or is it the case that the SiI 3132 does not support AHCI and that is > the reason for the difference? Does it make any difference in > performance? Hardly -- if these are true SATA controllers. MBR, Sergei