From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Adams Subject: r8169 performance? Date: Sun, 4 Dec 2011 15:10:07 -0600 Message-ID: <20111204211007.GA32098@hiwaay.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: netdev@vger.kernel.org Return-path: Received: from fly.hiwaay.net ([216.180.54.1]:51493 "EHLO fly.hiwaay.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753262Ab1LDVgW (ORCPT ); Sun, 4 Dec 2011 16:36:22 -0500 Received: from fly.hiwaay.net (localhost.localdomain [127.0.0.1]) by fly.hiwaay.net (8.13.8/8.13.8/fly) with ESMTP id pB4LA71e015564 for ; Sun, 4 Dec 2011 15:10:07 -0600 Received: (from cmadams@localhost) by fly.hiwaay.net (8.13.8/8.13.8/fly-submit) id pB4LA7xU015563 for netdev@vger.kernel.org; Sun, 4 Dec 2011 15:10:07 -0600 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: I have a system with an on-board RealTek gigabit network interface that is giving me poor performance. I'm using a simple test, running "nc -l" on one system and "dd if=/dev/zero | nc" on another. I see about 280 Mbps transmit and 511 Mbps receive. I checked the obvious things (cable, switch port) but they didn't seem to be the source of the problem (and nothing is showing any errors). I have another system with a different motherboard (different manufacturer) but with an onboard NIC that appears the same chip from lspci and dmesg (and they both appear to be wired up to PCI-E). It gets over 900 Mbps in the same type test. I'm running Fedora (64 bit) on my systems; I upgraded the "problem" system to F16 with kernel 3.1.2. Are there any suggestions for what I might be able to do to improve throughput? Is there a driver issue, or is it in how the motherboard implemented the NIC? Here's the lspci -vv output for the "problem" card. 02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03) Subsystem: ASRock Incorporation Motherboard (one of many) Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- SERR- Systems and Network Administrator - HiWAAY Internet Services I don't speak for anybody but myself - that's enough trouble.