On Mon, 16 Aug 2010 21:11:04 +0300 Auke Kok <auke-jan.h....@intel.com> wrote:
> On 08/15/2010 02:51 AM, tobias appelo wrote: > > Hi there, > > > > I was wondering what's the best way to reduce gpu power usage on a > > server or desktop that is not required to run X. It appears to me that > > this is still very common and I would like to save as much pwer as possible. > > I did some testing on desktops / laptops with intel integrated graphics, > > a desktop with an nvidia card and a desktop with an integrated ati video > > card and in each case the amount of watts that the whole system used > > (measured from wall) became less after initialization of X. (saved > > around 5 watts). > > Turning the monitor off using xrandr saved 5 watts more. > > In case of the nvidia and ati card I used the proprietary driver as it > > gave me better results when starting X. > > Simply modprobing the graphis driver did not lower the amount of watts > > used. Also, experimenting with underclockutilities such as rovclock or > > nvclock did not produce the same amount of powersaving (only about 3 > > watts) as just starting X. > > Currently I use a fluxbox setup to get the power usage as low as > > possible (and xrandr automatically turns off the monitor using fluxbox > > startup file), but I do not like installing all kinds of X software on > > systems that do not require it. Is there another way to reduce the GPU > > power usage in console mode ? > > Well, you could remove the power-hungry graphics card alltogether. This > might be an option if the system has on-board graphics. > > Intel's gfx chipsets will use kernel-modesetting which means that the > graphics chipset will be fully initialized at boot time and you'll get > the powersavings that way without running Xorg at all. Right, loading the i915 driver with KMS enabled should reduce the power usage to a lower level. Having all the VGA hardware enabled costs a lot of power on recent chips; it's provided for compatibility only and we don't put much effort into optimizing its power consumption. A simple console will be missing support for framebuffer compression though, so you won't see best case power consumption when you're using fbcon with the i915 driver. -- Jesse Barnes, Intel Open Source Technology Center _______________________________________________ Discuss mailing list Discuss@lesswatts.org http://lists.lesswatts.org/listinfo/discuss
