I'd like to confirm and elaborate on irwjager's recent findings. I allowed the computer to boot unplugged. I then connected the power after booting had completed.
Not only are C-states available, but the laptop's CPU temperature at idle is considerably cooler. /proc/acpi/thermal_zone/TZ01/temperature reads 38 C at idle instead of 55 C when booted with the power connected. So, now, my "notebook" computer cool enough to be a "laptop" for web browsing! On a hunch, I decided to do some computing benchmarks. I downloaded http://voxel.dl.sourceforge.net/project/systester/systester/1.1.0/systester-1.1.0 -linux-amd64.tar.bz2. (It's like superpi, but open source.) I extracted it and ran "./systester-cli -gausslg 2M -threads 1 -bench" (2 million digits of pi, 1 thread). Booted on battery, stay unplugged: not tested Booted on battery, then plugged in: 31-33 seconds Booted on A/C, still plugged in: 51-53 seconds! Booted on A/C, then unplugged: 90-93 seconds! For reference, you can compare my laptop dmesg outputs: http://qabe.net/envy15/files/dmesg.log http://qabe.net/envy15/files/dmesg_booted_on_battery.log You can clearly see C-states being initialised when booted on battery as well as some other differences -- including a segfault in the HPET code! -- No fans, thermalzone on HP Envy 15 and HP DV6T Quad https://bugs.launchpad.net/bugs/463940 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
