From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stan Hoeppner Subject: Re: kernel 2.6.31.1 + Sil 3512 + WDC WD5000AAKS-00V1A0 = no NCQ and UDMA5 instead of UDMA6 Date: Thu, 17 Dec 2009 21:49:49 -0600 Message-ID: <4B2AFBDD.30601@hardwarefreak.com> References: <4B2A3D25.9030209@hardwarefreak.com> <4B2A720B.2040809@pobox.com> <4B2AE779.9060109@hardwarefreak.com> <4B2AF2C2.9010708@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mo-65-41-216-221.sta.embarqhsd.net ([65.41.216.221]:33204 "EHLO greer.hardwarefreak.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753553AbZLRDtv (ORCPT ); Thu, 17 Dec 2009 22:49:51 -0500 In-Reply-To: <4B2AF2C2.9010708@pobox.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik Cc: linux-ide@vger.kernel.org Jeff Garzik put forth on 12/17/2009 9:10 PM: > Nope. You are pretty much maxing out the drive, of whatever drive you > plug in. The sata bus -- at its hardware spec'd maximum -- is far > faster than just about any drive, and the PCI bus is far faster than the > sata bus. I'm on the old 32bit/33MHz PCI bus of 133MB/s. SATA1 at 150MB/s is slightly faster, no? No argument here that both are far faster than almost all drives on the market. I was just wondering if bumping up from the default UDMA/100 to UDMA/133 would allow quicker PCI bus bursting and thus a slight improvement in overall performance. > You could probably max out the SATA bus with a RAM-based SATA device; > that's it. Yeah, I've seen some results published of quality SSDs and they just absolutely scream in latency, IOPs, and throughput. That's not in my future, it's complete overkill for my applications, performance and dollar wise. I just want to optimize the performance of what I already have. I think I only gave $15 for this Koutech Sil3512 PCI (32/33) controller at Newegg. You being you with the knowledge you have, would buying one of the cards whose chipset supports NCQ, such as the sata_sil24 cards, be anything close to worth the additional investment in dollars and time spent swapping hardware and drivers? Is NCQ the performance panacea that some purport it to be? How much difference does it really make? Thanks again for your time and advice Jeff. -- Stan