From owner-freebsd-hackers Sat Jul 17 15:38: 6 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from verdi.nethelp.no (verdi.nethelp.no [158.36.41.162]) by hub.freebsd.org (Postfix) with SMTP id C83C614F6B for ; Sat, 17 Jul 1999 15:37:56 -0700 (PDT) (envelope-from sthaug@nethelp.no) Received: (qmail 60049 invoked by uid 1001); 17 Jul 1999 22:37:53 +0000 (GMT) To: vince@venus.GAIANET.NET Cc: tim@storm.digital-rain.com, freebsd-hackers@FreeBSD.ORG Subject: Re: poor ethernet performance? From: sthaug@nethelp.no In-Reply-To: Your message of "Sat, 17 Jul 1999 14:25:41 -0700 (PDT)" References: X-Mailer: Mew version 1.05+ on Emacs 19.34.2 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Date: Sun, 18 Jul 1999 00:37:53 +0200 Message-ID: <60044.932251073@verdi.nethelp.no> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > It meets the spec when shipped but the bends, curves, temperature > and other factors do affect the performance. I guess a good way to test > the cable is with FreeBSD since it's the only real OS I've seen that can > do like real world speeds. The only thing is that has anyone really saw > 12 Megabytes/sec Full Duplex under FreeBSD? If you mean mega = 1048576, it's impossible since this is faster than 100 Mbps whichever way you count it. If you mean mega = 1000000, it depends on which way you're counting. The "speed of light" for TCP, application to application, on 100 Mbps Ethernet is 100 * 1460/1538 = 94.93 Mbps. This assumes full duplex. I've measured 94.87 Mbps myself on full duplex 100BaseTX (back to back with a crossover cable or through a switch). This is close enough to the "speed of light" that I see no point in trying to improve on it... Steinar Haug, Nethelp consulting, sthaug@nethelp.no To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message