From owner-freebsd-net@FreeBSD.ORG Sat Nov 5 15:32:43 2011 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id AB3D4106564A for ; Sat, 5 Nov 2011 15:32:43 +0000 (UTC) (envelope-from rmacklem@uoguelph.ca) Received: from esa-annu.mail.uoguelph.ca (esa-annu.mail.uoguelph.ca [131.104.91.36]) by mx1.freebsd.org (Postfix) with ESMTP id 65CE28FC1E for ; Sat, 5 Nov 2011 15:32:43 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AhgFAKRPtU6DaFvO/2dsb2JhbABDhHqjboIlgXIBAQEBAgEBAQEgBCcgCwUWGAICDRkCKQEJJg4CBQQBGgIEh2EIpGeRF4EwhmWBFgSSBIIdkgg X-IronPort-AV: E=Sophos;i="4.69,460,1315195200"; d="scan'208";a="142792502" Received: from erie.cs.uoguelph.ca (HELO zcs3.mail.uoguelph.ca) ([131.104.91.206]) by esa-annu-pri.mail.uoguelph.ca with ESMTP; 05 Nov 2011 11:03:50 -0400 Received: from zcs3.mail.uoguelph.ca (localhost.localdomain [127.0.0.1]) by zcs3.mail.uoguelph.ca (Postfix) with ESMTP id E85EDB3F06; Sat, 5 Nov 2011 11:03:50 -0400 (EDT) Date: Sat, 5 Nov 2011 11:03:50 -0400 (EDT) From: Rick Macklem To: bevan@bi-co.net Message-ID: <1893638131.1215459.1320505430915.JavaMail.root@erie.cs.uoguelph.ca> In-Reply-To: <1320494003.19667.41.camel@bevan-pc.fritz.box> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [172.17.91.201] X-Mailer: Zimbra 6.0.10_GA_2692 (ZimbraWebClient - FF3.0 (Win)/6.0.10_GA_2692) Cc: freebsd-net@freebsd.org Subject: Re: Gigabit Ethernet performance with Realtek 8111E X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 05 Nov 2011 15:32:43 -0000 bevan wrote: > Hi! >=20 > I've got a small NAS with Intel D525MW (Atom) board inside using > FreeBSD > 9.0-RC1 as operating system. It has an onboard Realtek 8111E ethernet > adapter. I'm experiencing heavy performance problems when transfering > files from a specific PC in my network to that NAS. I did the > following > tests by transfering large amount of data between the diferrent > machines > (using dd and nc): >=20 > NAS -> Linux1: ~ 400Mbit/s > NAS -> Linux2: ~ 400Mbit/s > Linux1 -> NAS: heavy fluctuation, between 700Mbit/s and 0bit/s > Linux2 -> NAS: ~ 400Mbit/s > Linux1 -> Linux2: ~ 400Mbit/s > Linux2 -> Linux1: ~ 400Mbit/s >=20 > As you can see everythink works fine except for transfering data from > Linux1 to that NAS box. The following graph shows the problem: > http://dl.dropbox.com/u/25455527/network-problems.png >=20 > While the transfer rate drops to zero the NAS also has a very bad ping > up to one second. Ping of Linux1 is perfectly fine during these > outages. >=20 > I also had a quick look on the data stream with wireshark on Linux1 > and > it shows a lot of TCP Dup ACK (up to 263 Dup ACKs created by NAS for > one > frame). >=20 > What can be eliminated as a cause is: > - Switch (I tried connecting Linux1 and NAS directly) > - Cable (I changed that a few times) > - Harddisk I/O (I'm only writing from /dev/zero to /dev/null) >=20 > The sevirity of that problem varies from one minute to another but can > always be reproduced with a few tries. >=20 > When limiting either NAS or Linux1 to 100Mbit I'm getting a steady > transfer rate of about 90Mbit/s. > When decreasing the MTU on NAS to 1200 the problem seems to disappear, > getting a transfer rate of about 160Mbit/s. >=20 > ifconfig re0: > > re0: flags=3D8843 metric 0 mtu > > 1500 > > =09options=3D388b > > =09ether 38:60:77:3e:af:a5 > > =09inet 192.168.178.54 netmask 0xffffff00 broadcast 192.168.178.255 > > =09nd6 options=3D29 > > =09media: Ethernet autoselect (1000baseT ) > > =09status: active >=20 try typing: # sysctl dev.re.0.stats=3D1 - this will dump out the stats on the chip if the "Rx missed frames" count is non-zero, you're probably snookered, to put it technically:-) - That's what I get for a re chip is this laptop and I haven't found a way around it. I just live with flakey net performance. rick > pciconf -lv: > > re0@pci0:1:0:0: class=3D0x020000 card=3D0xd6258086 chip=3D0x816810ec > > rev=3D0x06 hdr=3D0x00 > > vendor =3D 'Realtek Semiconductor Co., Ltd.' > > device =3D 'RTL8111/8168B PCI Express Gigabit Ethernet controller' > > class =3D network > > subclass =3D ethernet >=20 > Because Linux1 seems to be involved in that problem: It's running > Linux > 3.0 and it has an "Atheros Communications AR8121/AR8113/AR8114" > onboard. >=20 > Does anyone have an idea what could be the problem here? Decreasing > the > MTU is some kind of solution but the performance is still not optimal > and a MTU of 1500 should be no problem. >=20 > Greetings, > Michael La=C3=9F >=20 > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"