From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mogens Valentin Subject: Re: Ultra160 controller on 32bit pci Date: Thu, 06 May 2004 17:51:33 +0200 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <409A5F05.A7FA9935@danbbs.dk> References: <4099F408.E424C26A@danbbs.dk> <20040506152923.GB2281@parcelfarce.linux.theplanet.co.uk> Reply-To: monz@danbbs.dk Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from pfepb.post.tele.dk ([195.41.46.236]:7519 "EHLO pfepb.post.tele.dk") by vger.kernel.org with ESMTP id S262768AbUEFPtQ (ORCPT ); Thu, 6 May 2004 11:49:16 -0400 List-Id: linux-scsi@vger.kernel.org To: Matthew Wilcox Cc: Linux-scsi Matthew Wilcox wrote: > > On Thu, May 06, 2004 at 10:15:04AM +0200, Mogens Valentin wrote: > > Currently using Adaptec 29160, works fine, but it's only 160/2, after > > all. > > I'm curious if other controllers can provide better performance when > > used on a 32bit pci bus? > > Theoretical bandwidth on a 33MHz 32-bit PCI bus is around 132MB/s. > In practice you never attain that because of overhead in turning the bus > around and typical figures quoted in the PCI spec are between 60-107MB/s. > So you already saturated the PCI bus (never mind what else you have on > that bus). I'm aware of that. I have a 40MHz pci bus, no problems with any devices (most modern cards are build for 66MHz anyway), so I'm interested in scsi controllers possible utilising a 32bit interface better (than the 29160). Haven't seen any though, thus the question. > > In a few month I might switch to a pci-express/opteron setup, so I'd > > like some indication about controllers for that bus. > > Depends what people are going to ship. I've heard rumours the initial > chipsets will have an x16 link for graphics and an x4 link for other I/O. Yes, a few such boards already exist. No matter which combinations will be on boards, I'll be happy with on x16 slot for video and one x-whatever for a scsi controller. Thanks for replying.. -- Kind regards, Mogens Valentin Networking, Security www.danbbs.dk/~monz Phone +45 32 525 878