X300 power consumption - take 2
Posted by George Wright Tue, 30 Dec 2008 03:16:00 GMT
Trying out Debian Lenny and its power management seemed to help; I can now get the machine down below 8W, and when using it on half brightness with the wireless card turned on, it sits at around 9W. This isn’t too bad anymore. It’s certainly a lot better than Ubuntu’s 12W in approximately the same circumstances - a saving of 25%!
I’ve now compiled a custom 2.6.28 kernel on Lenny and tried out the ASPM PCI-Express power management code that’s marked as experimental. dmesg reports the following on bootup:
[ 0.172338] ACPI FADT declares the system doesn't support PCIe ASPM, so disable it
After commenting out that bit of code in the kernel just to see what would happen, I then echoed “powersave” to /sys/module/pcie_aspm/parameters/policy, with no noticeable decrease in power usage.
The brightness issue is now sorted. After installing guidance power manager in KDE3 on Lenny things just worked. Sort of. The brightness levels reported by guidance are slightly wrong and the range is wrong. I suspect this is because previous thinkpads have had 7 brightness levels and this one has 15.
The touchpad issue, I’ve concluded, is a limitation of the hardware rather than the software, which is unfortunate. It seems that Lenovo changed the touchpad brand from Synaptics to ALPS with recent models. Unfortunately, ALPS touchpads are nowhere near as good as Synaptics ones, and so I’m stuck with a touchpad that’s a bit of a pain to use. Basically, if you press a button on one mouse, X receives a button press event. However, if you then keep it held down and move the other mouse, the mouse automatically generates a button release event before sending the new motion events. Thank you ALPS.
The fan is now being controlled in userspace using tpfand. I have built debian packages of version 0.94 (from the Ubuntu sources) and I will upload them at some point, along with the fan profile I’m using.
One last thing - the SSD in this machine is blisteringly fast. hdparm brings up around 90MB/s and Lenny cold-boots in about 20 seconds to the kdm login screen.
Re: touchpad, my notebook has an Elantech touchpad that works just how you described and I actually find it useful to prevent accidental taps. Drag and drop works by doubletapping and holding the second tap and then dragging.
What kind of filesystem do you use for the SSD as it arready has a internal wear levelling mechanism?
@lariamat: These SSDs are just like normal HDDs to the Operating system, so I guess he just uses ext3.
Do you know what Lenny does differently than Ubuntu? My Dell Latitude E6400 also sits around 11-12W with Ubuntu 8.10 and according to Windows Vista I should get much more battery life.
@blueget: It makes sense to not use ext3 so the SSD doesn’t wear out by the constant updating of the journal, that’s what lariamat is referring to.
How do you know the power consuption of your system?
I’m using powertop.
Don’t know if you’re aware of it: Your blog appears on planet.gnome.org “Random bloggings of a clearly disturbed KDE geek” mmmm….
Of course I’m aware of it! :) I’m a KDE person through and through but I have been known to work on GNOME-related projects…
ah ok. thanks for the reply
The touchpad and trackpoint work fine together with Windows Vista: holding down the left button below the touchpad and moving the red knob works. Either it’s not a limitation of the hardware or Vista has some quirks to work around it.
It would be nice to see that working in linux.
Can you provide somewhere the X300-profile for tpfand? Thanks Ben