From owner-freebsd-questions Sun Jan 27 14: 5:28 2002 Delivered-To: freebsd-questions@freebsd.org Received: from imo-m02.mx.aol.com (imo-m02.mx.aol.com [64.12.136.5]) by hub.freebsd.org (Postfix) with ESMTP id E885F37B402 for ; Sun, 27 Jan 2002 14:05:26 -0800 (PST) Received: from TD790@aol.com by imo-m02.mx.aol.com (mail_out_v31_r1.26.) id g.15d.7fa5980 (4330); Sun, 27 Jan 2002 17:04:41 -0500 (EST) From: TD790@aol.com Message-ID: <15d.7fa5980.2985d379@aol.com> Date: Sun, 27 Jan 2002 17:04:41 EST Subject: Re: UDMA and 100Mbit NIC speed issues To: neil@neilmcgann.co.uk, kstewart@owt.com Cc: freebsd-questions@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: AOL 5.0 for Windows sub 138 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG In a message dated 1/27/02 4:03:42 PM Eastern Standard Time, neil@neilmcgann.co.uk writes: > Realistically 100Mb/sec is flat out > for 33MHz PCI and trying to get some bandwidth for the NIC may just not be > do-able. Its more like 400Mb/s, but highly dependent on what else is on the bus. 100Mb/s is what you'll get with single quadword transactions, but any burstable bus-master will be able to do substantially better than that. You can do routing with dual full duplex 100Mb/s ethernets without seeing xmitter underruns, which requires 400Mb/s across the bus. A 3rd nic or disk transactions will cause problems beyond that. db To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message