> >> Hi, >> >> I'm working on DELL E7440 platform (Haswell based) with dual OS: Windows >> 8.1 >> and Ubuntu 14.04.1 (based on 3.13). >> When I use Win 8.1, using BLA I get ~90% PC7 when idle. However, when I >> use >> the Ubuntu, using powertop I get only as high as PC3. >> Since it's the same platform, it seems to rule out a HW issue. Any idea >> what >> can be the problem? Is Haswell fully supported by powertop? >> >> Package | Core | CPU 0 CPU 2 >> | | C0 active 0.2% 0.1% >> | | POLL 0.0% 0.0 ms >> 0.0% >> 0.0 ms >> | | C1E-HSW 0.0% 0.1 ms >> 0.0% >> 0.0 ms >> C2 (pc2) 0.1% | | >> C3 (pc3) 3.7% | C3 (cc3) 0.0% | C3-HSW 0.0% 0.4 ms >> 0.0% >> 0.4 ms >> C6 (pc6) 0.0% | C6 (cc6) 0.0% | C6-HSW 0.0% 0.0 ms >> 0.0% >> 0.2 ms >> C7 (pc7) 0.0% | C7 (cc7) 99.0% | C7s-HSW 0.1% 0.9 ms >> 0.1% >> 1.8 ms >> C8 (pc8) 0.0% | | C8-HSW 0.1% 1.4 ms >> 0.2% >> 2.5 ms >> C9 (pc9) 0.0% | | C9-HSW 0.4% 4.0 ms >> 2.3% >> 8.0 ms >> C10 (pc10) 0.0% | | C10-HSW 98.9% 44.5 ms >> 97.0% >> 36.5 ms >> >> | Core | CPU 1 CPU 3 >> | | C0 active 0.2% 0.1% >> | | POLL 0.0% 0.0 ms >> 0.0% >> 0.0 ms >> | | C1E-HSW 0.0% 0.0 ms >> 1.0% >> 50.1 ms >> | | >> | C3 (cc3) 0.0% | C3-HSW 0.0% 0.7 ms >> 0.0% >> 0.6 ms >> | C6 (cc6) 0.0% | C6-HSW 0.0% 0.5 ms >> 0.0% >> 0.0 ms >> | C7 (cc7) 98.0% | C7s-HSW 0.1% 0.7 ms >> 0.4% >> 25.7 ms >> | | C8-HSW 0.0% 4.9 ms >> 0.0% >> 1.5 ms >> | | C9-HSW 0.6% 4.7 ms >> 0.7% >> 19.5 ms >> | | C10-HSW 98.5% 93.5 ms >> 97.8% >> 78.0 ms >> >> | GPU | >> | | >> | Powered On 12.1% | >> | RC6 87.9% | >> | RC6p 0.0% | >> | RC6pp 0.0% | >> >> Thanks >> >> >> >> Rony >> >> _______________________________________________ >> PowerTop mailing list >> PowerTop(a)lists.01.org >> https://lists.01.org/mailman/listinfo/powertop >> Hi Rony, Interesting you ask this since I presented at the Open source bridge conference a case study on how to optimize your computer in terms of power using PowerTOP, as an example I used a Haswell box with Ubuntu. I also presented on the Debian conference a similar talk using Debian distro. Both talks happened this year. There are few things that may be happening. 1- Update to the latest kernel 3.17. From 3.13 to 3.17 there have been few bug fixes that help linux in terms of power management. 2-At the boot command line of your kernel add the following settings: i915.enable_psr=1 i915.enable_fbc=1 pcie_aspm=force The first command enables the graphics card use panel self refresh, the second enables frame buffer compression. The third command helps the network card enter D3 state. http://wireless.kernel.org/en/users/Documentation/ASPM#Enabling_ASPM_with... 3- Use PowerTOP/tunables to tune power management for all your devices. If none of the settings disrupt the proper usability of the computer add then to a script file and run this each time you restart your computer. Alternatively you can use powertop --auto_tune Run PowerTOP at this point you should see your system reaching a deep power state. Thank you, Alexandra.