Hi, Thanks for the suggestions. I tried the following, which didn't change much the situation. Can it be that the CPUs just warm up more when getting old, or it shouldn't matter if cleaned properly?
a) I disassembled and cleaned the fan. Fairly dusty (it's about 5 years I have the laptop), I used a vacuum cleaner to remove the dust. I have the impression that the fan now pushes out more air. b) I installed and configured thinkfan (despite the buggy installation [1]). The package description [2] says it is helpful in the case the fan is running too much (not really my problem), but it actually provides an easy way in general to set the fan levels for given temperature ranges [3]. In comparison to before, the fan runs faster now when above 60C. c) I also tried to turn on by hand the disentangled mode (~5500rpm instead of ~4500rpm) [4]. d) I had a look to the script suggested by Tom (thanks), but didn't try it since I managed to install thinkfan. FYI, I think that /proc/acpi/ibm/thermal is no longer the way to get the temperature. For "normal" use (browsing, video, music, ...) the temperature stays below 60C using thinkfan. When I run with CPUs at 100% it reaches 90C in less than two minutes. For work I need to launch short (few minutes) but CPU expensive runs (mostly numerical integrations) on a daily basis. I'll ask around if someone can lend me one of those fan pads to try it out. Thanks, Francesco 1. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=767127 2. https://packages.debian.org/jessie/thinkfan 3. http://forums.debian.net/viewtopic.php?t=118734 4. http://www.thinkwiki.org/wiki/How_to_control_fan_speed On Fri, Jun 17, 2016 at 7:27 PM, Sven Arvidsson <s...@whiz.se> wrote: > On Fri, 2016-06-17 at 12:58 +0300, Francesco Montanari wrote: > > Hi, > > > > I recently installed Jessie on a Lenovo ThinkPad T420. The fan usage > > looks > > reasonable. However, high temperatures (96 C) are reached when CPUs > > are > > running intensively for more than one minute or so. The fan speed at > > those > > temperatures is about 4500 rpm. > > > > Do you think it is ok, or do you suggest to force lower temperatures, > > e.g., > > with thinkfan [1]? > > It isn't unusual with a temperature like that during load, but it > mostly seems to happen when playing demanding games on a laptop. > > I wouldn't worry about it if it just happens momentarily, but long > running tasks that stress the system like that is probably not suitable > on a laptop. > > Anyway, as others have pointed out, check for dust and make sure that > you don't impede air flow yourself (by placing it on bed for example). > > -- > Cheers, > Sven Arvidsson > http://www.whiz.se > >
