[ltp] Excessive power consumption: x220 with Fedora 15

[Dmitry E. Mikhailov]

On Thursday 11 August 2011 23:33, Christos Papadopoulos wrote:
> Powertop reports 16-17W with machine idle. Unit is X220-4286, Intel
> graphics and network. Is this normal? Any ideas how to reduce it?

Conditions are not really well defined.
16W at near-full brightness with Compiz enabled, Firefox with 50 tabs opened 
and flash-animated advertisements, wireless connected could be quite normal.

Try:
brightness at minimum (or comfort readable minimum),
wireless disabled (or check that wireless power saving mode is supported and 
used, check AP so it wouldn't send every beacon as "wakeup"-packet), 
bluetooth disabled,
set kernel laptop-mode to 5, 
mount partitions with noatime (saves quite a bit of power actually if not 
compiling smth on a battery), 
try aggressive power saving features of your HDD with hdparm (caution - it 
could shorten the HDD life and/or decrease reliability in the long run)
check pcie_aspm enabled (could affect stability),
check sata alpm enabled,
unload usb 1.1 modules (effectively disabling it),
disable ethernet or go to lower speed (gigabit to 100mbit may save over a 
watt),
disable ethernet wake-on-lan (saves power in S3/STR suspend),
check if CPU is using ondemand governor (almost sure it does already),
don't use compiz (or any other 3D/compositing desktop graphical candy),
try sched_smt_power_savings=1,
try video framebuffer compression,
disable unused video outputs,
check vm writeback time, try increasing (the chance of data loss increases 
also),
disable syslog,
check audio codec power saving enabled.

Report again.


Best regards,
	Dmitry Mikhailov.