Thanks for the update. On Thursday, May 21, 2015, Stefan Sperling <s...@stsp.name> wrote:
> On Wed, May 20, 2015 at 08:56:57PM -0600, Shaun Reiger wrote: > > Hello I'm trying to find out if the power consumption relating to the > > intel_powerclamp driver ("Package Level C-state Idle Injection for > > Intel CPUs") was ever fixed. I'm current running 5.7 stable and I find > > my cpu is still consuming 6W of power in any state. It was mentioned > > in the emails from last year that a Linux driver fixed this issue. Any > > updates on this issue would be great. I have attached my dmesg for > > review. > > > > Thanks > > There was some work in progress for C-state support by guenther@ but > I'm not sure what the current status is. I got about one additional > hour of battery life out of it when I tested it once. With plain > -current I get about 2h of runtime out of the battery. > > Getting to the levels of Linux (additional 4 hours in my case) probably > requires invasive changes to the process scheduler (prevent it from > scheduling processes on certain cores to avoid waking them) and/or the > inteldrm(4) driver (to put the GPU into power-save mode). > > It seems the x201 has a CPU generation which requires a ton of special > support code in drivers for good power saving, while subsequent > generations of laptops (x220 and later) use CPUs which don't really > require that much of it. Overall I'm not sure it's really worth pouring > a lot of development resources into optimizing for the x201 generation. > Other laptops already run much longer. > -- Shaun "Ars longa, vita brevis, occasio praeceps, experimentum periculosum, iudicium difficile" - Hippocrates (c. 400BC)