From owner-freebsd-stable@FreeBSD.ORG Wed Sep 9 04:21:43 2009 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A8903106566C for ; Wed, 9 Sep 2009 04:21:43 +0000 (UTC) (envelope-from mav@FreeBSD.org) Received: from cmail.optima.ua (cmail.optima.ua [195.248.191.121]) by mx1.freebsd.org (Postfix) with ESMTP id 30B5D8FC08 for ; Wed, 9 Sep 2009 04:21:42 +0000 (UTC) Received: from [212.86.226.226] (account mav@alkar.net HELO mavbook.mavhome.dp.ua) by cmail.optima.ua (CommuniGate Pro SMTP 5.2.9) with ESMTPSA id 253799936; Wed, 09 Sep 2009 07:21:40 +0300 Message-ID: <4AA72D4D.9080505@FreeBSD.org> Date: Wed, 09 Sep 2009 07:21:33 +0300 From: Alexander Motin User-Agent: Thunderbird 2.0.0.23 (X11/20090901) MIME-Version: 1.0 To: Daniel O'Connor References: <1252426982.00160755.1252414203@10.7.7.3> <4AA6860F.1020203@FreeBSD.org> <200909091018.10509.doconnor@gsoft.com.au> In-Reply-To: <200909091018.10509.doconnor@gsoft.com.au> X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: 7bit Cc: FreeBSD Stable Subject: Re: Detecting CPU throttling on over temperature X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Sep 2009 04:21:43 -0000 Daniel O'Connor wrote: > On Wed, 9 Sep 2009, Alexander Motin wrote: >> Daniel O'Connor wrote: >>> I recently discovered a system where the floppy drive cable was >>> intermittently fouling the CPU fan - I believe this caused the CPU >>> to overheat and then get throttled by the BIOS. >>> >>> Does anyone know if it is possible to determine if this is the >>> case? ie is there a way to be informed if throttling has occurred? >> Theoretically it is possible. I know off-topic tool reporting this. >> Also you can just monitor CPU temperature, depending on CPU type. > > Monitoring CPU temperature is a bit difficult, there are a lack of tools > (although I have some code it's not complete). There indeed problems with MB monitoring, as it is non-standard. But modern CPUs also include on-chip thermal sensors. For Core2Duo family coretemp module works fine and precisely. > The problem is that the CPU temperature is only a proxy measurement, I > would much prefer to be told directly the BIOS is throttling rather > than guess :) While ACPI could implement thermal throttling, AFAIK TM1/TM2 technologies of P4 and above families are working just in CPU hardware. BIOS only initializes them. -- Alexander Motin