From mboxrd@z Thu Jan 1 00:00:00 1970 From: Riccardo Veraldi Subject: Re: Very bad Speed with Virtio-net Date: Thu, 07 Jan 2010 12:21:56 +0100 Message-ID: <4B45C3D4.8010800@cnaf.infn.it> References: <4B45BCEA.1040709@googlemail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, Andrea Chierici To: Benjamin Schweikert Return-path: Received: from iris.cnaf.infn.it ([131.154.3.7]:54735 "EHLO iris.cnaf.infn.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751818Ab0AGLWK (ORCPT ); Thu, 7 Jan 2010 06:22:10 -0500 In-Reply-To: <4B45BCEA.1040709@googlemail.com> Sender: kvm-owner@vger.kernel.org List-ID: I have similar results, like yours, using CentOS 5.4 x86_64 I do not think it is possible to gain more than this right now... or better I wish it could be possible If you can get better result please let me know Rick Benjamin Schweikert wrote: > Hello everybody, > this is my first post on a mailing list, so i hope everything works fine. > > My host is a AMD X2 4850e with a 64bit Gentoo (unstable). I have > tested qemu-kvm 0.11, 0.12.x and the git version from the 6. jan. > I created my own bridges, so i dont need the option from libvirt. I > bridged a 1 Gb lan card for my VMs. When I use the virtio net driver, > i get something about 200-300 mbit form my desktop to one if my VMs. > If iI use the e1000 driver instead of the virtio I get about > 500 - 600 mbit. > I tested this with the following kernels: > Host: 2.6.31.6, 2.6.32.1, 2.6.32.2 > Guests: 2.6.26, 2.6.30, 2.6.32 (debian) > 2.6.32 (gentoo) > > Here is a default result, virtio vs. e1000: > > iperf -c 192.168.0.3 -w 512k -l 512k > ------------------------------------------------------------ > Client connecting to 192.168.0.3, TCP port 5001 > TCP window size: 256 KByte (WARNING: requested 512 KByte) > ------------------------------------------------------------ > [ 3] local 192.168.0.2 port 52968 connected with 192.168.0.3 port 5001 > [ ID] Interval Transfer Bandwidth > [ 3] 0.0-10.0 sec 438 MBytes 267 Mbits/sec > > > iperf -c 192.168.0.3 -w 512k -l 512k > ------------------------------------------------------------ > Client connecting to 192.168.0.3, TCP port 5001 > TCP window size: 256 KByte (WARNING: requested 512 KByte) > ------------------------------------------------------------ > [ 3] local 192.168.0.2 port 52995 connected with 192.168.0.3 port 5001 > [ ID] Interval Transfer Bandwidth > [ 3] 0.0-10.0 sec 602 MBytes 505 Mbits/sec > > Any ideas what this could be? I attach a dmesg output of my host. > Thx. > > Ben