Re: enable i915 rc6 save 7 watt on kernel 3.2
Am Donnerstag, 19. Januar 2012 schrieb Chen Wei:
> On Thu, Jan 19, 2012 at 10:29:19AM +0100, Martin Steigerwald wrote:
> > merkaba:~> cat /etc/modprobe.d/i915-kms.conf
> > options i915 modeset=1 i915_enable_rc6=1 i915_enable_fbc=1
> > semaphores=1
> >
> > There is also
> >
> > # The Leading Cause Of The Recent Linux Kernel Power Problems
> > #
> > http://www.phoronix.com/scan.php?page=article&item=linux_2638_aspm&n
> > um=2 GRUB_CMDLINE_LINUX_DEFAULT="pcie_aspm=force threadirqs"
> >
> > but I didn´t found it to make much of a difference on my ThinkPad
> > T520.
>
> same model here. Power consumption is fluctuate between 14 to 15W. With
> pcie_aspm=force, the reading appears lower by less than 1W, it could be
> an equipment error. So the difference is small, if any, with the
> pcie_aspm tweak. Besides, aspm seems remain disabled:
>
> wei@Tungsten:~$ dmesg|grep -i aspm
> [ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-3.2.1
> root=UUID=ed888aee-0822-4303-8bea-18f0fbf9ba3a ro quiet pcie_aspm=force
> threadirqs
> [ 0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-3.2.1
> root=UUID=ed888aee-0822-4303-8bea-18f0fbf9ba3a ro quiet pcie_aspm=force
> threadirqs
> [ 0.000000] PCIe ASPM is forcibly enabled
> [ 0.460586] ACPI FADT declares the system doesn't support PCIe ASPM,
> so disable it
> [ 0.582432] ACPI _OSC control for PCIe not granted, disabling ASPM
Well AFAIR the second message is overridden by the first one in that case.
Would have to lookup the details from some Phoronix articles by Michael
Larabel or some other sources or the linux kernel source.
> > Aside from that glxgears is not, was not and likely never will be a
> > meaningful benchmark - it only utilizes a tiny fraction of OpenGL
> > while games and compositing managers use a different and larger set
> > of OpenGL. There are some benchmarks at Phoronix that show increased
> > framerates. One suggested explaination there is that due to the
> > power savings mechanisms like turbo boost for overclocking can be
> > used more often and/or longer.
>
> they are over several hundred MB. Is there any small and simple graphic
> test tool like glxgreas?
Well what exactly do you want to test and why?
Thanks,
--
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7
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