Date: Fri, 04 Mar 2005 10:43:53 -0800 From: "Kevin Oberman" <oberman@es.net> To: jesse@wingnet.net Cc: freebsd-mobile@freebsd.org Subject: Re: Thinkpad Thermals Message-ID: <20050304184353.9A3B65D07@ptavv.es.net> In-Reply-To: Your message of "Fri, 04 Mar 2005 13:01:21 EST." <d08t8d$tg3$1@sea.gmane.org>
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> From: Jesse Guardiani <jesse@wingnet.net> > Date: Fri, 04 Mar 2005 13:01:21 -0500 > Sender: owner-freebsd-mobile@freebsd.org > > Howdy! > > My IBM Thinkpad A30p's ATI video chip got cooked last year, > leaving me with an unreadable screen full of artifacts. I > finally bought a replacement mobo a few days ago and installed > it this evening. It's now running artifact free! Yay! > > Anyway, I'm no longer running FreeBSD on this laptop. I'm > currently running Gentoo Linux. But it would be trivial > to switch back if needed. > > I'm using gkrellm under linux to monitor my CPU temp, and > I'm noticing that it runs quite hot. The fan doesn't kick > in until the CPU hits 80C! That's a little too close for > comfort, IMO. > > I think I remember seeing other posts from Thinkpad users > mentioning high temps under ACPI. Has anyone found a way > to cool these things down? Jesse, Is it running at or near 80C when idle, when in typical use, or when building something BIG (CPU running at >95% for minutes). I believe that the A30p is a P4-M CPU. It will turn itself off (hard, like a power cut-off) before the CPU dies, but that is NOT a good thing. That does not happen until the CPU reaches a frightening 135C. If you are running 5-Stable or 6-Current you should load cpufreq and acpi_perf. These will give you a large number of CPU "frequencies" visible in dev.cpu.0 and settable in dev.cpu.0.freq. This provides fine-grained control. Yo can also look at hw.acpi.0.thermal for _PSV and _CRT. _PSV is the temperature at which the CPU should start to slow down to moderate the temperature. _CRT is the point at which alarms are sounded and the OS should start a clean shutdown. If there is no cooling problem _PSV should keep the temperature from ever reaching _CRT. You will note that these temperatures are WAY under 135C, but the 135C cutoff is intended for catastrophic failures (like a broken/improperly installed heat sink) and assumes that the temperature rose very quickly. It is not intended that the CPU should run at that sort of temperature normally. FreeBSD is still working on support for all of this, but it's getting much closer. The addition of powerd to Current is a big step, but it is probably not quite ready for prime time and is disabled by default. Nate just committed it to current a few days ago and I just installed it yesterday, so I have no experience with it. Bottom line is that as long as the temperature stays below _PSV under heavy load, you should not be concerned. If it exceeds _PSV for very long, you might want to reduce dev.cpu.0.freq a bit. If you ever hit _CRT, dow something quickly. FWIW, my system has _PSV at 86.5C and _CRT at 94.0C, so 80C is really not that hot, though my thigh does not agree when my laptop is literally on my lap. As always, I am not really an expert on all of this and I can hope that Nate or someone else will correct any errors in this. -- R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634
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