Thinkpad CPU temperature reaches 100°C after 10 minutes of heavy use

Question

Less than two years ago, I bought a Lenovo Thinkpad R500.

When using the CPU heavily, it sometimes decides to reboot.

I am using Linux, and a widget shows me the CPU temperature. The PC usually reboots when the temperature of the first core gets over 100°C

Since I switched from Ubuntu 2010.10 32bit to Ubuntu 2011.04 64bit, it crashes much more often.

I survive using these techniques:

1. When in the office, I use a laptopcooler.
2. When outside, I underclock to 800 MHz, by doing so it does not get too warm.

QUESTION:

Is it normal that a Thinkpad crashes if the CPU is at 100% for more than 10 minutes?

How can I use the full power of my computer, for instance when showing CPU-hungry business intelligence tools to clients?

The computer does not really feel that hot. Maybe the sensor itself is reporting wrong temperatures? Can I tell the BIOS to ignore it?

Answer 1

Forget Thinkpad for a moment, It isn't normal for any laptop to crash when at 100% cpu for a long period of time, but it is normal for nearly all machines to shut down, if any monitored component reaches a critical temperature.

It simply means your fans/cooling are not sufficient or up to the job.

Firstly, as Egon said in comments, check for a BIOS update - if others have complained of similar problems, it is usual for manufacturers to release updates that either underclock certain components or increase fan speed/thresholds.

If this doesn't help, you may want to check for dust and dirt that is clogging up fans.

Finally, if you find anyone else with similar problems, you may want to complain direct to the manufacturer.

It is possible that the sensor is wrong, but, it is always hard to prove, other than by opening up and using a thermometer.

... In addition, I am out of the loop, but have read about Linux power issues which would obviously cause more heat to build up - that being said, this should only affect battery life... but, it doesn't solve the underlying issue with regards to the cooling of your laptop.

Answer 2

Two things you can do:

1. Hardware-side: clean the dust

   As your laptop is about 2 years old, a lot of dust could have built up in the cooling system. You have two options: clean it yourself or give the laptop to a local computer service point for cleaning.

2. Software-side: try undervolting

Check out the linux-PHC project. Very often, the default voltages of processors are set significantly above the reasonable level. This was the case for my Thinkpad.

Answer 3

Fun fact about Thinkpads (at least my model): the GPU is located physically very close to the CPU and thus is capable of tripping the CPU heat sensor despite the GPU's being configured for a higher temperature. If you set your widget to display GPU as well, you might notice that number being just as high if not higher.

Many models of Thinkpad have "switchable" graphics; if you use the higher-end card under linux, you'll want to install the proprietary Catalyst drivers, as I've found the generic ones have a bug which causes the GPU to heat up rapidly.