Date: Sat, 17 Jul 1999 16:01:40 -0700 (PDT) From: Vincent Poy <vince@venus.GAIANET.NET> To: sthaug@nethelp.no Cc: tim@storm.digital-rain.com, freebsd-hackers@FreeBSD.ORG Subject: Re: poor ethernet performance? Message-ID: <Pine.BSF.4.05.9907171554280.331-100000@venus.GAIANET.NET> In-Reply-To: <60227.932251891@verdi.nethelp.no>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, 18 Jul 1999 sthaug@nethelp.no wrote: > > 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 guess I forgot about the overhead. I've tested between two FreeBSD machines using Intel Pro100+ NIC cards connected to a Cisco 2924XL Switch Full Duplex and never seen anything close to the speeds. > > > 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 :-) Hmmm, how did you do the measurement and how big of a file does it need? With a 122MByte file, it only does 2644Kbytes/sec. This is between two Pentium II 450 machines with Intel Pro100+ NICs. Cheers, Vince - vince@MCESTATE.COM - vince@GAIANET.NET ________ __ ____ Unix Networking Operations - FreeBSD-Real Unix for Free / / / / | / |[__ ] GaiaNet Corporation - M & C Estate / / / / | / | __] ] Beverly Hills, California USA 90210 / / / / / |/ / | __] ] HongKong Stars/Gravis UltraSound Mailing Lists Admin /_/_/_/_/|___/|_|[____] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.4.05.9907171554280.331-100000>