From owner-freebsd-current@FreeBSD.ORG  Wed Jan 14 11:03:42 2004
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id B538F16A4CE
	for <freebsd-current@freebsd.org>;
	Wed, 14 Jan 2004 11:03:42 -0800 (PST)
Received: from mailhub1.midco.net (mailhub1.midco.net [24.220.0.32])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 7CED643D1D
	for <freebsd-current@freebsd.org>;
	Wed, 14 Jan 2004 11:03:41 -0800 (PST)
	(envelope-from pmes@bis.midco.net)
Received: (qmail 17639 invoked by uid 0); 14 Jan 2004 19:03:41 -0000
Received: from host-195-219-220-24.midco.net (HELO bis.midco.net)
	([24.220.219.195])          (envelope-sender <pmes@bis.midco.net>)
	by lvs-pop.midco.net (qmail-ldap-1.03) with SMTP
	for <andrew@shavers.co.uk>; 14 Jan 2004 19:03:41 -0000
Message-ID: <4005928C.6050507@bis.midco.net>
Date: Wed, 14 Jan 2004 13:03:40 -0600
From: Peter Schultz <pmes@bis.midco.net>
User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.6b) Gecko/20031215
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: "Andrew Edwards (Olympic Shaver Centre)" <andrew@shavers.co.uk>
References: <003c01c3da8f$c022a3e0$0b00a8c0@laptop>
In-Reply-To: <003c01c3da8f$c022a3e0$0b00a8c0@laptop>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
cc: freebsd-current@freebsd.org
Subject: Re: Hyperthreading with SMP in 5.2
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 14 Jan 2004 19:03:42 -0000

Andrew Edwards (Olympic Shaver Centre) wrote:
> Could anyone clarify the level of support for Pentium 4
 > hyperthreading in 5.2?

Virtual SMP lags as literal SMP still isn't even fully tuned.

 > i.e if I run a single cpu heavy process, whereas without
 > hyperthreading I would see 100% usage now I only see around 50%.
 >

The program itself has got to be written with SMP in mind in order to 
accomplish that.

You'll never have perfect CPU utilization.  Maybe with some 
superconductive quantum computer or some such futuristic thing.  :-)

Pete...