From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: Virtualization Performance: Intel vs. AMD Date: Mon, 16 Nov 2009 13:02:23 +0100 Message-ID: <877htq65kg.fsf@basil.nowhere.org> References: <200911151054.57510.tfjellstrom@shaw.ca> <4B0080C2.1010309@bobich.net> <200911151603.40453.tfjellstrom@shaw.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org To: tfjellstrom@shaw.ca Return-path: Received: from one.firstfloor.org ([213.235.205.2]:58121 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752739AbZKPMCT (ORCPT ); Mon, 16 Nov 2009 07:02:19 -0500 In-Reply-To: <200911151603.40453.tfjellstrom@shaw.ca> (Thomas Fjellstrom's message of "Sun, 15 Nov 2009 16:03:40 -0700") Sender: kvm-owner@vger.kernel.org List-ID: Thomas Fjellstrom writes: > Hardware context switches aren't free either. FWIW, SMT has no "hardware context switches", the 'S' stands for simultaneous: the operations from the different threads are travelling simultaneously through the CPU's pipeline. You seem to confuse it with 'CMT' (Coarse-grained Multi Threading), which has context switches. -Andi