From owner-freebsd-current@FreeBSD.ORG Tue Jun 1 17:03:06 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A138B16A4CE for ; Tue, 1 Jun 2004 17:03:06 -0700 (PDT) Received: from odin.ac.hmc.edu (Odin.AC.HMC.Edu [134.173.32.75]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6AB8643D5E for ; Tue, 1 Jun 2004 17:03:04 -0700 (PDT) (envelope-from brdavis@odin.ac.hmc.edu) Received: from odin.ac.hmc.edu (IDENT:brdavis@localhost.localdomain [127.0.0.1]) by odin.ac.hmc.edu (8.12.10/8.12.10) with ESMTP id i51N0ISK020319 for ; Tue, 1 Jun 2004 16:00:18 -0700 Received: (from brdavis@localhost) by odin.ac.hmc.edu (8.12.10/8.12.3/Submit) id i51MxNm6020266; Tue, 1 Jun 2004 15:59:23 -0700 Date: Tue, 1 Jun 2004 15:59:23 -0700 From: Brooks Davis To: Luke Message-ID: <20040601225922.GA20044@Odin.AC.HMC.Edu> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="C7zPtVaVf+AK4Oqc" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.4i cc: freebsd-current@freebsd.org Subject: Re: Cap on network speed in CURRENT? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Jun 2004 00:03:06 -0000 --C7zPtVaVf+AK4Oqc Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jun 01, 2004 at 03:38:18PM -0700, Luke wrote: >=20 > I've got a 100Mbps LAN with ethernet cards that should be capable of usin= g=20 > it, yet the highest transfer rates I seem to be able to get out of my=20 > FreeBSD box are 260KB/s receiving and 341KB/s sending with around 200KB/s= =20 > being more normal. >=20 > I realize that there are hundreds of factors that could be influencing=20 > this, but I came across this recent article that made me wonder if this i= s=20 > some kind of hardcoded limit: > http://www.freebsd.org/news/status/report-jan-2004-feb-2004.html#Automati= c-sizing-of-TCP-send-buffers >=20 > Is this article saying that my network speed is limited by a small=20 > static TCP buffer size? If so, is there some way that I can increase tha= t=20 > buffer size to improve performance? The primary function of this machine= =20 > is to move large amounts of data across my network, so I'm willing to=20 > experiment with increasing the buffer size if it's not too difficult. On a LAN, buffer size has minimal effect except at very high speeds. Without tuning, two 5.x boxes with gigabit interfaces connected to a Cisco 6513 switch (one 5/10/04 and one 2/20/04) reached 187Mbps in iperf. You're problems symptoms sound like duplex mismatch or bad hardware to me. -- Brooks --=20 Any statement of the form "X is the one, true Y" is FALSE. PGP fingerprint 655D 519C 26A7 82E7 2529 9BF0 5D8E 8BE9 F238 1AD4 --C7zPtVaVf+AK4Oqc Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQFAvQpKXY6L6fI4GtQRAg8uAKDBCZpB6c5rjs7bEtb2irpILJcS5ACfVeLD /bh/RE7DKj6VkSHsOHm3p4o= =RVXA -----END PGP SIGNATURE----- --C7zPtVaVf+AK4Oqc--