Tuesday 18 March 2014

Keeping cool with thermald

The push for higher performance desktops and laptops has inevitably lead to higher power dissipation.  Laptops have also shrunk in size leading to increasing problems with removing excess heat and thermal overrun on heavily loaded high end machines.

Intel's thermald prevents machines from overheating and has been recently introduced in the Ubuntu Trusty 14.04 LTS release.  Thermald actively monitors thermal sensors and will attempt to keep the hardware cool by modifying a variety of cooling controls:
 
* Active or passive cooling devices as presented in sysfs
* The Running Average Power Limit (RAPL) driver (Sandybridge upwards)
* The Intel P-state CPU frequency driver (Sandybridge upwards)
* The Intel PowerClamp driver

Thermald has been found to be especially useful when using the Intel P-state CPU frequency scaling driver since this can push the CPU harder than other CPU frequency scaling drivers.

Over the past several weeks I've been working with Intel to shake out some final bugs and get thermald included into Ubuntu 14.04 LTS, so kudos to Srinivas Pandruvada for handling my patches and also providing a lot of timely fixes too.

By default, thermald works without any need for configuration, however, if one has incorrect thermal trip settings or other firmware related thermal zone bugs one can write one's own thermald configuration. 

For further details, consult the Ubuntu thermald wiki page.

5 comments:

  1. Hm. Did you manage to track down why “start on dbus” sometimes brought thermald up before the sysfs paths were ready?

    ReplyDelete
    Replies
    1. File a bug, assign it to me and I will check it out

      Delete
    2. Nope, it's still got that 5 second wait in it. Urgh.

      Delete
  2. So Thermald will work without Pstate being enabled on Ubuntu 14.04?

    ReplyDelete
  3. Yes, it will work OK without pstate enabled too.

    ReplyDelete