Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 6 Mar 2003 02:47:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 6 Mar 2003 02:47:01 -0500 Received: from mx2.it.wmich.edu ([141.218.1.94]:55201 "EHLO mx2.it.wmich.edu") by vger.kernel.org with ESMTP id ; Thu, 6 Mar 2003 02:47:00 -0500 Message-ID: <3E66FF6B.2060301@wmich.edu> Date: Thu, 06 Mar 2003 02:57:31 -0500 From: Ed Sweetman User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20030206 MIME-Version: 1.0 To: Corvus Corax CC: linux-kernel@vger.kernel.org Subject: Re: Linux vs Windows temperature anomaly References: <20030303123029.GC20929@atrey.karlin.mff.cuni.cz> <3E66842F.9020000@WirelessNetworksInc.com> <200303061038.44872.kernel@kolivas.org> <20030306081804.4717d1c4.corvusvcorax@gemia.de> In-Reply-To: <20030306081804.4717d1c4.corvusvcorax@gemia.de> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4127 Lines: 96 This is getting kicked like a deadhorse by now i think but. Unlike your cpu which gets idle commands from the OS and thus has an idle loop where it turns off certain circuits and which can get acpi commands to turn completely off the other chips in the computer do not have such a luxury. they are always on like the cpus of yesteryear used to be. It doesn't matter if they have data moving in them or not, no big difference. The reason why it seems like this is the case is for you HSF cooled cpu guys, load on the system bus usually means high cpu load and that means more heat put into the surrounding air and the little usually passive cooled but regardless, less hot system bus gets hotter along with the cpu and cooler when the cpu is idle. People cooled by other methods that do not dump heat into the surrounding air inside the case will notice that the system bus temp only varies with ambient air temp changes, not data transfer going on between ram and cpu. Corvus Corax wrote: > Am Thu, 6 Mar 2003 10:38:44 +1100 > schrieb Con Kolivas : > > >>That doesn't make sense. His post said the temperature was 20 degrees lower >>when it failed. >> >>Con > > > I think it does, > > look at this: > > RAM > ._____________________. > _|| | | | | | | | | | ||_. ._/| ._/| > / ||___________________|| |~\ ||/| ||/| > | |O _____ O| |~\\ /||/| ||/| > | | .-?| | |?-. | |\\\\ //|| | || | > | | / \ |~| | / \ | |\\\\\ //=|| |=|| | > | | /| |\| |~|/| |\ | |\\\\.________. ///=||/|=||/| > | | * | | \_._/ |~| * | |\===| |==///==||/|=||/| > | | |~|~| /CPU\ ~ | | | |====| north |==///==|| |=|| | > | | | | |~\_ _/ | | | | |====| bridge |=======|| |=|| | > | | * | | / ? \ | |~* | |/===| (MEM ) |=======||/|=||/| > | | \| |/| |~|\|~|/ | |//==| (CTRL) |==\\\==||/|=||/| > | | \ / |~| | \ / | |////?~~~~~~~~?==\\\==|| |=|| | > | | ?-.|_|_|.-? | |///// |||||| \\\=|| |=|| | > | |O O| |//// |||||| \\=||/|=||/| > | |~~~~~~~~~~~~~~~~~~~~~| |_// |||||| \\||/| ||/| > ?~|| | | | | | | | | | ||~?_/ |||||| \|| | || | > ?~~~~~~~~~~~~~~~~~~~~~? |||||| ||/ ||/ > CPU TEMP | |||||| |_| |_| > | | voltage |||||| > | ||| |||||| > | ||| .________. > Mainboard | ||| | | > TEMP .,,,,,,. data | south | > O | |=======| bridge | > \\_____?''''''? | (BUS ) | > ?~~~~~~? | (CTRL) | > TEMP & ?~~~~~~~~? > VOLTAGE ctrl ////|||\\\\\ > chip PCI & other BUS > > > the sensor for the system temperature (somewhere on the board) is connected to a driver chip (usually on the i2c bus) > like the w83781d (on my board) > > if something now causes the (often badly cooled) bridge to get hot (by more load between some periphery and the RAM for example) > , the system temperature doesnt necessary have to increase. > > if the bridge has only a heatsink, its temperature is somewhat like > (system TEMP)+ ( produced heatper time / heat given to the air by heatsink per time ) > where the heatsinks capacity is dependent on the delta temperature, too, gets complicated ;) > > in short, the chips hotter than the rest of the system and if it has high load it gets even hotter, > but its temp is still dependant on the main system TEMP. ;) > > blahrgh forget what i talk, watch the ASCII art, and imagine the effect of much data running between > BUS and RAM ;-) (or BUS and BUS if north and southbridge are on the same chip) > > CvC > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/