On Wed, 2016-04-06 at 22:13 -0400, Matthew Gabeler-Lee wrote: > The throttling to "50%" ends up mapping to "always stuck at the bog minimum > slowest speed possible". >
What hardware are you on? There's a recent kernel fix in the thermal subsystem, which affected many users. https://bugzilla.kernel.org/show_bug.cgi?id=114551 https://bugzilla.redhat.com/show_bug.cgi?id=1317190 > cpufreq-info -c 0: > driver: intel_pstate > CPUs which run at the same hardware frequency: 0 > CPUs which need to have their frequency coordinated by software: 0 > maximum transition latency: 0.97 ms. > hardware limits: 800 MHz - 3.00 GHz > available cpufreq governors: performance, powersave > current policy: frequency should be within 800 MHz and 3.00 GHz. > The governor "powersave" may decide which speed to use > within this range. > > Even running burnP6 * nCPUs from cpuburn won't bump it off the bare minimum > 800MHz when on battery. > I think this is more to do with the kernel, as is reported in the bug reports above. > My cpu is a: > model name : Intel(R) Core(TM) i7-4500U CPU @ 1.80GHz That is almost what I have. model name : Intel(R) Core(TM) i7-4510U CPU @ 2.00GHz > > Which I guess explains why "50%" is "800MHz" -- 3GHz is the max turbo freq, > 800MHz is presumably the only step close to 1800/2=900 MHz. > > >From what I've read, preventing the CPU from bumping up to higher > frequencies can actually *increase* power consumption because it forces the > CPU to stay awake longer before returning to an idle low power / sleep > state. > > Needless to say I'm fixing this locally in my config files, but I would > suggest that the current defaults should be revisited as producing poor > behavior, and possibly being misguided. I am open to re-visit, provided there is substantial input. I have the same make hardware but I don't see the problem reflect as severe on my box. -- Ritesh Raj Sarraf | http://people.debian.org/~rrs Debian - The Universal Operating System
signature.asc
Description: This is a digitally signed message part