From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757473AbYEJCUd (ORCPT ); Fri, 9 May 2008 22:20:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752424AbYEJCUW (ORCPT ); Fri, 9 May 2008 22:20:22 -0400 Received: from elasmtp-curtail.atl.sa.earthlink.net ([209.86.89.64]:39637 "EHLO elasmtp-curtail.atl.sa.earthlink.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751800AbYEJCUU (ORCPT ); Fri, 9 May 2008 22:20:20 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=mindspring.com; b=FaNu4V4B26j9OHnivG+YqsCLLkyMtyVRFdWW0vzA3ExKhIOBx2BrNB5ejeHzkIE6; h=Received:Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References:X-Mailer:Mime-Version:Content-Type:Content-Transfer-Encoding:X-ELNK-Trace:X-Originating-IP; Date: Fri, 9 May 2008 22:20:06 -0400 From: Bill Fink To: Jesper Krogh Cc: Rick Jones , David Miller , yhlu.kernel@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: NIU - Sun Neptune 10g - Transmit timed out reset (2.6.24) Message-Id: <20080509222006.6a43e740.billfink@mindspring.com> In-Reply-To: <4824D4C0.10201@krogh.cc> References: <86802c440805071130m62c1f4edydb3316dac4a2aba2@mail.gmail.com> <20080507.141521.193714938.davem@davemloft.net> <482498D5.9060008@krogh.cc> <20080509.143229.174354251.davem@davemloft.net> <4824C936.9000103@krogh.cc> <4824CE43.8060203@hp.com> <4824D4C0.10201@krogh.cc> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.8.6; powerpc-yellowdog-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-ELNK-Trace: c598f748b88b6fd49c7f779228e2f6aeda0071232e20db4dfc12f65a0d9fb33f664baf5ca6048164350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 96.234.158.248 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 10 May 2008, Jesper Krogh wrote: > Rick Jones wrote: > > > > Into which slot was the Neptune inserted? (sure will be nice to have > > Alex Chiang's pci slot id patch in mainline one of these days :) > > > > Is that slot x4, x8, x16? > > I can find out excactly .. on monday. But shouldn't x4 be enough anyway? > wikipedia says 250MB/s pr. lane. And no slots is less than x4, so I > thought that it didn't matter to me. No you need 8x for 10-GigE. The 250 MB/sec per lane is 2 Gbps per lane so 4x is only 8 Gbps. For a typical PCI-E transaction size of 128 bytes, and PCI-E protocol overhead of 20 to 24 bytes, that takes off about 20%, which leaves you with about 6.5 Gbps of usable bandwidth, which is further reduced somewhat by the required PCI-E ACK and flow control packets that accompany the actual data transaction packets. I am not an expert on PCI-E but I believe this info to be generally correct. -Bill