Not completely true for a 1:1 comparison. Verify that your WiFi is entering D3, as earlier testing showed Dell specific WiFi parts (on Linux) were not enabling ASPM. On Windows this is enabled by the driver. Best walk through for it: http://wireless.kernel.org/en/users/Documentation/ASPM From: PowerTop [mailto:powertop-bounces@lists.01.org] On Behalf Of Rony Ross Sent: Tuesday, October 28, 2014 9:21 AM To: powertop(a)lists.01.org Subject: [Powertop] Package C states over Haswell platform 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