

New Linux kernel fixes power-saving issues - nickolai
http://www.h-online.com/open/news/item/New-Linux-kernel-fixes-power-saving-issues-1429482.html

======
nwj
Very excited about this. My T410 has a noticeably shorter battery life when
running arch compared to windows. This will help close that gap a bit.

~~~
hannes2000
Does it have Optimus, i.e. two graphics chips? Which chip do you use more
often? I keep my T410 exclusively running on the power-hungry nVidia chip and
don't get more than 2hrs of battery life.

~~~
nwj
It does have Optimus and the battery life is about where yours is - maybe 2.5
hours.

I'm running the nVidia chip exclusively, but when I get around to it, I'll
probably switch, as I'm running an openbox desktop that just doesn't need that
kind of graphics acceleration. I have yet to figure out a painless way of
switching between the two, but that's probably because I haven't really worked
on it much.

~~~
simcop2387
There's no current way to switch painlessly, but there is something that makes
it slightly nicer than having to restart all of your programs. Check out
Bumblebee [1]. It does it by running two X servers, one for the lower power
system and another for the NVIDIA binary blob and plays with environment
variables to get things working. Then it takes the NVIDIA server and copies
the images over to the slower card. In a round about way it's what windows
systems do for it, but not quite as sane and not quite as performant. There's
been some work to create the sharing needed so that drivers can share the
buffers directly and eventually there won't need to be the second X server.
However this also depends on if that work either gets its license changed or
NVIDIA GPLs the kernel bits to their driver.

[1] <https://wiki.archlinux.org/index.php/Bumblebee>

------
fl3tch
Good news. It should be noted that Ubuntu has included this fix since their
distro version 3.0.0-13, and other distros may have backported the fix, too.
But now it's in mainline.

------
jrockway
Nice. My X220 already has seemingly-infinite battery life, so this should be
even better.

~~~
mapleoin
I have an X220, too, but it only has ~3 hrs battery life. Where did you buy
yours?

~~~
jrockway
I have two, one for work and one I bought myself from Lenovo. They both get
about 8 hours battery life with the 9-cell battery.

~~~
bo1024
Mine too, but it runs very hot and gets significantly less battery on Linux
than Windows. (How you know something's wrong.)

I tried a fix or two as suggested, but they didn't help; I hope the kernel
upgrade does it!

~~~
jrockway
I don't know how mine compares to Windows, but it doesn't run particularly
hot. I don't use anything fancy on my Linux boxes; xmonad and some terminals
on my home machine, xmonad and GNOME on my work machine. Very low-CPU :)

------
avallark
"The patch only has this effect on systems with the firmware problem detailed
above, which can be identified by using dmesg to display kernel messages and
looking for the message "ACPI FADT declares the system doesn't support PCIe
ASPM, so disable it"." >> Not for all!

