From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: How to determine performance bottleneck? Date: Tue, 14 Oct 2008 14:37:41 +0900 Message-ID: <48F43025.8050705@kernel.org> References: <20081013202836.3fc62c3e@mjolnir.drzeus.cx> <48F3D8E2.8000006@kernel.org> <20081014070728.386a9cf2@mjolnir.drzeus.cx> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from hera.kernel.org ([140.211.167.34]:34186 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750958AbYJNFjp (ORCPT ); Tue, 14 Oct 2008 01:39:45 -0400 In-Reply-To: <20081014070728.386a9cf2@mjolnir.drzeus.cx> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Pierre Ossman Cc: Jeff Garzik , linux-ide@vger.kernel.org Pierre Ossman wrote: > On Tue, 14 Oct 2008 08:25:22 +0900 > Tejun Heo wrote: > >> Pierre Ossman wrote: >>> When I'm accessing a single disk, the bandwidth is 70 - 80 MiB/s. When >>> I access a second disk, the bandwidth is about 50 MiB/s/disk, and all >>> five results in 25 MiB/s/disk. In other words, something is limiting >>> things to about 100 MiB/s. Now the question is what that limiting >>> factor is. >>> >> That's the limit of sil3124/3132. Dunno why but you can't go over that. > > Bummer. Is this per port, or is it the PCIe side of the chip that is > limited to this speed? I think it's on the host bus side. > What do the silicon image guys have to say about it? ISTR they confirmed the problem but I don't remember talking too much about it. >> There's 3132-2 chip on the market. Maybe it's worth a try? > > Now that model number was not something that was easily found on > google, nor on silicon image's website. Know of any boards with that > chip? Somebody wrote me an email about it. Looking up... eh.. can't find. Sorry. -- tejun