From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 6 Aug 2002 12:44:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 6 Aug 2002 12:44:41 -0400 Received: from dhcp101-dsl-usw4.w-link.net ([208.161.125.101]:61670 "EHLO grok.yi.org") by vger.kernel.org with ESMTP id ; Tue, 6 Aug 2002 12:44:40 -0400 Message-ID: <3D4FFDBD.8070100@candelatech.com> Date: Tue, 06 Aug 2002 09:47:57 -0700 From: Ben Greear Organization: Candela Technologies User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.1b) Gecko/20020722 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Willy Tarreau CC: Robert Latham , linux-kernel@vger.kernel.org Subject: Re: tigon3: 2466 and bad performance at 32bits/33mhz ? References: <20020806053508.GJ25554@mcs.anl.gov> <20020806084840.GB32229@alpha.home.local> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Willy Tarreau wrote: > On Tue, Aug 06, 2002 at 12:35:08AM -0500, Robert Latham wrote: > >>The fast curve is with the 3c996B-T in the 64/66 slot. It peaks out >>around 850 Mbps. The slow curve is the same card in the 32/33 slot. >>It peaks around 180 Mbps. > > [snip] > >>So, am i looking at a hardware limitation? driver quirk? I'm open to >>any suggestions. > > > on a 32/33 slot, with a quad fast ethernet card, I can reach 400 Mbps > on good hardware. The *theorical* bandwidth limit is 1.06 Gbps for > 32 bits/33 Mhz. Of course, there's some overhead, but you would need 80% > overhead to get you numbers, not very likely... > > Perhaps this slot is on another bus, perhaps the latency timer is too > low and the card receives small chunks at once, or perhaps this bus > is shared with another hungry device ? > > Regards, > willy I'm pushing 650Mbps on a 32/33 PCI bus using a Netgear GA620 GigE card (the card supports 64bit PCI). So, its not exactly a PCI bus limitation you are hitting unless your PCI chipset somehow really sucks. Ben > > - > 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/ > -- Ben Greear President of Candela Technologies Inc http://www.candelatech.com ScryMUD: http://scry.wanfear.com http://scry.wanfear.com/~greear