x220 power consumption comparison?

altercation · 2011-11-22 22:34:23

I'm tweaking power consumption on my ThinkPad x220 tablet and am curious what others are seeing on kernel 3.1+

Right now with wifi on in console only I'm seeing a consistent 6.2-6.3 watts. I've had it drop down to 5.7 but can't get that level consistently. I think this is about as low as I'm going to get it right now (without undervolting) and I'm curious to see what others are running at.

Anyone else with an x220 / x220 tablet care to weigh in?

Last edited by altercation (2011-11-22 22:35:10)

lagagnon · 2011-11-24 02:09:52

Are you bragging? ;-) That is an incredibly low number for a laptop, at least the 4-7 year old laptops I have had. I am lucky to get it down to 14 watts on my Toshiba L300. I would be interested to know what you are measuring that number with and how? Because I doubt you will beat it! I measure my total laptop consumption at the wall with a Kill-A-Watt meter. Because that is the number that counts...if that is what you get with proper watt meter you should be more than satisfied!

steve___ · 2011-11-24 02:21:35

I haven't upgraded my laptop since July 08. Powertop says I get between 8w and 9w with firefox running. I'd also like to know how you're measuring this.

altercation · 2011-11-24 03:56:57

Console only for 6.2-6.3. Xmonad running with chrome open right now is hovering around 9.1-9.6.

I'm not so concerned with power consumption under X since it can vary a lot, which is why I was testing mostly in virtual consoles as a baseline.

I'm testing with:

powertop2

and

watch -dn1 "acpitool -B"

@lagagnon I'm glad to hear this sounds like a brag ... I thought that with the new power fixes I'd see far below this in just virtual console with no X running. I expected down around 3 or 4. I believe that windows can achieve that level of power savings on the x220. Not giving up yet, but until more work is done on the ASPM power saving support, I suppose this is the floor.

Last edited by altercation (2011-11-24 03:57:11)

altercation · 2011-11-24 04:39:27

I'm going to order a killawatt as well. I have a whole house wattage monitor that is shockingly accurate, but I think a plug based unit is better for this test.

Haptic · 2011-11-24 06:34:08

What are your boot options? I have a T420 which is just a larger screen version of the X220 (minus the tablet). I can't even get it under 9 without running X.

altercation · 2011-11-24 06:40:05

Haptic wrote:

What are your boot options? I have a T420 which is just a larger screen version of the X220 (minus the tablet). I can't even get it under 9 without running X.

Current boot options:

linux /vmlinuz-linux root=/dev/mapper/root ro cryptdevice=/dev/sda3:root add_efi_memmap \
i915.modeset=1 pcie_aspm=force i915.i915_enable_rc6=1 i915.i915_enable_fbc=1 i915.lvds_downclock=1 quiet¬

I suspect the powersaving options I trigger in my /etc/acpi/handler.sh are also related. I'll push that to github and post here.

Last edited by altercation (2011-11-24 06:41:18)

altercation · 2011-11-24 06:52:53

Here you go:

https://github.com/altercation/x220-arc … handler.sh

The _Powersave () function is probably most relevant.

OpenBSD · 2011-11-26 01:50:39

http://techpatterns.com/forums/about1963.html

5.4W with liquorix kernel with integrated power saving patch

Pank · 2011-11-26 02:39:01

I am using the pk kernel floating around these forums and the most recent version works amazing for me! Today, without wifi during lecture I was between 4-5 watts on a x200s.

Probably, if I integrated all of your tweaks I could gain more.

Thanks,

David Batson · 2011-11-26 03:54:03

I have a X220 with the IPS display and Intel Core i5 2540M cpu. I am running XFCE with Compiz. WiFi and Bluetooth radio off atm. No other special powersaving methods used.

i915.i915_enable_rc6=1 results in power savings. Get about 8.4 watts with display brightness set at half while on battery.

i915.i915_enable_fbc=1 results in an additional good 2 watts of power savings but causes glitches when watching videos in vlc. I decided not to use this option.

i915.lvds_downclock=1 has no noticible effect afaict. I decided not to use this option.

altercation · 2011-11-26 06:59:29

OpenBSD wrote:

http://techpatterns.com/forums/about1963.html
5.4W with liquorix kernel with integrated power saving patch

Interesting that pcie_aspm=force results in *higher* consumption after that patch. Is that with wifi on? If so, much closer to the windows levels.

rmnk · 2011-12-03 09:37:40

Here are my settings:

kernel /vmlinuz-linux root=/dev/sda7 ro \
i915.modeset=1 i915.i915_enable_rc6=1 i915.i915_enable_fbc=1 i915.lvds_downclock=1 pcie_aspm=force

But now I have 12-13W with BT, 60% brightness in firefox.
What do I do wrong?

powertop:

Cn                Avg residency       P-states (frequencies)
C0 (cpu running)        ( 3.0%)         2.10 Ghz     0.2%
polling           0.0ms ( 0.0%)         2.00 Ghz     0.0%
C1 mwait          0.3ms ( 0.2%)         1.91 Ghz     0.0%
C2 mwait          0.6ms ( 0.1%)         1.80 Ghz     0.1%
C3 mwait          1.3ms ( 0.0%)          800 Mhz    99.8%
C4 mwait         12.7ms (96.7%)
Wakeups-from-idle per second : 84.8     interval: 3.0s
Power usage (ACPI estimate): 0.7W (84.1 hours) (long term: 11.9W,/4.9h)

Top causes for wakeups:
  28.6% ( 81.0)   kworker/0:0
  23.0% ( 65.3)   kworker/0:1
  10.5% ( 29.7)   [kernel scheduler] Load balancing tick
  10.2% ( 29.0)   [i915] <interrupt>
   8.6% ( 24.3)   PS/2 keyboard/mouse/touchpad interrupt
   8.1% ( 23.0)   [acpi] <interrupt>
   5.3% ( 15.0)   firefox
   1.9% (  5.3)   [rtlwifi] <interrupt>
   1.6% (  4.7)   xmobar
   0.6% (  1.7)   [kernel core] hrtimer_start (tick_sched_timer)

Last edited by rmnk (2011-12-03 09:41:15)

altercation · 2011-12-03 21:26:15

rmnk wrote:

Here are my settings:
kernel /vmlinuz-linux root=/dev/sda7 ro \
i915.modeset=1 i915.i915_enable_rc6=1 i915.i915_enable_fbc=1 i915.lvds_downclock=1 pcie_aspm=force
But now I have 12-13W with BT, 60% brightness in firefox.
What do I do wrong?

I'd recommend installing powertop2 from AUR as it provides a better interface for testing power savings tweaks.

The sample ACPI handler.sh I posted ( https://github.com/altercation/x220-arc … handler.sh ) gives an example of a "brute force" power savings method that you can use. It might put some devices into powersave mode that you don't want to (i.e. the wacom touch screen shouldn't be put into powersave mode), but it's a good way to start developing a custom acpi handler for power savings.

bolshevik · 2011-12-07 14:48:04

With "i915.i915_enable_rc6=1", my 2.5ghz i5 does about ~10 watts with the brightness dimmed down one notch from max. That's how I mostly use it on battery and it gives me a solid 8 hours (with the 9-cell) of light office work, or 3-4 hours if streaming videos. With the brightness dimmed all the way down and wifi off I've seen ~6.5 watts, but that's just impractical. Tested with powertop2.

Arch Linux

#1 2011-11-22 22:34:23

x220 power consumption comparison?

#2 2011-11-24 02:09:52

Re: x220 power consumption comparison?

#3 2011-11-24 02:21:35

Re: x220 power consumption comparison?

#4 2011-11-24 03:56:57

Re: x220 power consumption comparison?

#5 2011-11-24 04:39:27

Re: x220 power consumption comparison?

#6 2011-11-24 06:34:08

Re: x220 power consumption comparison?

#7 2011-11-24 06:40:05

Re: x220 power consumption comparison?

#8 2011-11-24 06:52:53

Re: x220 power consumption comparison?

#9 2011-11-26 01:50:39

Re: x220 power consumption comparison?

#10 2011-11-26 02:39:01

Re: x220 power consumption comparison?

#11 2011-11-26 03:54:03

Re: x220 power consumption comparison?

#12 2011-11-26 06:59:29

Re: x220 power consumption comparison?

#13 2011-12-03 09:37:40

Re: x220 power consumption comparison?

#14 2011-12-03 21:26:15

Re: x220 power consumption comparison?

#15 2011-12-07 14:48:04

Re: x220 power consumption comparison?

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