From owner-freebsd-hackers Sat Jul 17 15:53: 7 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 EFDB114BEC for ; Sat, 17 Jul 1999 15:53:00 -0700 (PDT) (envelope-from sthaug@nethelp.no) Received: (qmail 60229 invoked by uid 1001); 17 Jul 1999 22:51:31 +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 15:43:22 -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 00:51:31 +0200 Message-ID: <60227.932251891@verdi.nethelp.no> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > I mean Mega as in 1000000. 100Mbps Ethernet should be equal to > about 12500Kbytes/sec which is equal to 12.5Mbytes/sec. 94.93Megabits/sec > doesn't equal to 100Megabits/sec. 12.5 Mbytes/sec on the wire *is* 94.93 Megabits/sec application to application using TCP - that's what I'm trying to say. You'll never see 12.5 Mbytes/sec application to application - look up the Ethernet frame formats to see why (1460 bytes of TCP payload is 1538 bytes on the wire). > > 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... > > Yeah but what's the transfer rate you get? 94.87 Mbps, application to application, using ttcp. Using Mega = 1000000, that should be 11.86 MBytes/sec. Oh yeah, this was measured with FreeBSD, with a P-133 on the receving end, back in '96 :-) 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