From mboxrd@z Thu Jan 1 00:00:00 1970 From: JR Subject: Poor performance with virtio network driver on windows 2008 R2 on KVM Date: Wed, 14 May 2014 11:37:25 -0400 Message-ID: <53738DB5.2050006@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: kvm@vger.kernel.org Return-path: Received: from mail-ig0-f179.google.com ([209.85.213.179]:51652 "EHLO mail-ig0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752479AbaENPh2 (ORCPT ); Wed, 14 May 2014 11:37:28 -0400 Received: by mail-ig0-f179.google.com with SMTP id hn18so1934538igb.6 for ; Wed, 14 May 2014 08:37:27 -0700 (PDT) Received: from [192.168.1.8] (cpe-67-241-20-7.twcny.res.rr.com. [67.241.20.7]) by mx.google.com with ESMTPSA id uf4sm6062380igc.18.2014.05.14.08.37.26 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 14 May 2014 08:37:26 -0700 (PDT) Sender: kvm-owner@vger.kernel.org List-ID: Greetings all, Though I don't believe that this is KVM problem per se, I'm seeing very poor network performance when using windows 2008R2 KVM instances with the virtio driver when on a 10G network. iperf results show linux VMs getting close to wire speeds, while windows only does about 1.3Gb/sec. I've tried a number of tcp settings (chimney, etc...) as recommended by some google searches but nothing has helped. Does anyone have any advice? Thanks much, JR -- Your electronic communications are being monitored; strong encryption is an answer. My public key