Usable time on battery: T61 Fedora 14

[Owlbrudder]

Folks, I have just recently found forum.thinkpads.com - what a great place!

My current problem: I am getting +/- 1 hour running time from a full battery. I was a little disappointed by that, but it has been consistent and is the same on both my batteries (I bought a spare when I bought the machine from new), so I just assumed that was as good as it gets. However, it looks as though I am well down on what I should expect. For example, in post http://forum.thinkpads.com/viewtopic.php?f=9&t=79474 , Rasmus writes: "PS: On my X60 I get around 6-7 hours when I have turned off wlan which is comparable to Windows". Yes, I know they are different machines - does that account for the whole difference?

I suspect the way I have set up my rig is chewing the charge unreasonably quickly. I have taken some good advice from other posts, such as how to shut down Bluetooth aggressively, and I always switch the wireless off using the little slider in the front of the keyboard bezel. Is there more I can do? Should I shut down background tasks like postgres and http? Would it help to switch off the Compiz window manager, to perhaps lower the graphics demand? (I am using the nVidia driver installed via "yum install nVidia", if that makes any difference)

I have no idea (apart from posts here) about what devices and applications I should be shutting down. I have just installed powertop (thanks again to posts here) and will use its suggestions next time I am away from mains power. What else can I do?

I would be interested to know what battery duration I should be aiming at. Even doubling it to 2 hours would make a huge difference and going out to 6 or 7 hours is beyond my wildest dreams!

BTW, I have been lurking and browsing battery topics here, but have not seen a thread dealing with the T61 battery runtime specifically - apologies if my question has already been answered.

EDIT: Just found http://www.thinkwiki.org/wiki/How_to_re ... onsumption - lots of good info here; not sure how up-to-date it is.

[GomJabbar]

I think I saw a related thread on the fedora forums. Someone mentioned installing Powertop to improve this (as best I remember).

[craigmontHunter]

I was playing with ubuntu the other day, and I was getting ~4 hours of battery life with wireless off I went back to vista, because it gives me ~5-5.5 hours (with wifi on), which are definately a huge help I understand that the nvida card will use more juice than intel, and that is possibly where your problem lies. Make sure that you have cpu throttling on, and see if there are any options for gpu power management - play around. I also reccomend powertop, it will let you see what programs are waking the CPU. Finally, try the 32-bit version (if you are not using it already), since IIRC it is "tickless" - it does not wake the cpu every once and a while, which apparently saves battery life.

The Nivida will definately limit your battery life to a couple of hours, you ar just going to have to play and see what works best.
Good luck

[Owlbrudder]

Nivida will definately limit your battery life to a couple of hours

Thanks for that. I will follow all the tips I can find and look to get my battery time up to a couple of hours. At least that saves me from worrying about trying to get 5 hours on a 2 hour system. "8-)

And thanks GomJabbar - I have installed powertop and will use it over Easter, when I will be camping, to see what difference it makes.

[Owlbrudder]

I will follow all the tips I can find

What an interesting process this has been. Thanks to all those who have posted tips in the past.

I now have my T61/FC14 x86_64 system spending 99.9% of its time with the processors (2.4Ghz Dual Core) ticking over at 800Mhz and 99.6% of its time in C3 state, according to powertop. Powertop does not show a division for C4 state, although I have read of it in various threads. Powertop remarks "Wakeups-from-idle per second : 40.6 interval: 15.0s" - is that good? Not knowing any better, I will say I have done as much as I can to save power.

Powertop also comments "no ACPI power usage estimate available", which means nothing to me - should I be concerned? I know the acronym stands for Advanced Configuration and Power Interface, but that is the limit of my knowledge on the subject.

What I have done so far:

• Ensured 'cat /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor' returns 'ondemand'. This is out of the box for my system.
• Ensured my nVidia settings are 'Adaptive' (System/Preferences/NVIDIA X Server Settings/PowerMizer)
• Used the switch on the front of the keyboard bezel to switch off all wireless devices
• Used a script I found elsewhere in this forum to unload my Bluetooth drivers completely
• Disabled unnecessary services like httpd, hsqldb and postgres
• Disabled my sound card (System/Preferences/Sound/Hardware/Profile = Off)
• Closed a slew of applications I normally leave open in case I want to refer to them. This included several instances of Firefox, each with numerous tabs open, which Powertop reported as causing a large number of wakeups on the processor.
• Switched off the Compiz windowing manager (System/Preferences/Desktop Effects = Standard)
• Unplugged my USB webcam.
• Turned my display backlight down as far as I can and still see to work.
• Adjusted my power management (System/Preferences/Power Management) settings for battery operation to:
• - Put computer to sleep when inactive for: 30 minutes
• - When laptop lid is closed: Hibernate
• - When battery power is critically low: Suspend
• - Spin down hard disks when possible: check
• - Put display to sleep when inactive for: 10 minutes
• - Reduce backlight brightness: check
• - Dim display when idle: check

Any suggestions for further pruning will be gratefully received.

I have read several posts from people who are quoting their consumption in watts. Is there any way of obtaining that figure from the system, or is it a matter of putting a meter on the mains plug?

I am going bush over Easter and plan to do some writing, if the lappy will stay awake long enough to make it worthwhile. If everything goes to plan, I will report back as to how I went with battery life.

Edit: It will be interesting to see how accurate the battery monitor prediction is. After 15 minutes on battery, with the above settings, it reported: "Laptop battery 4 hours 20 minutes remaining (96.3%)". If I really get anywhere near 4 hours, I shall be a happy little camper.

[GomJabbar]

I have read that the backlight of the display consumes a fair amount of power. To get maximum battery life, turn the display brightness down to the minimum acceptable level. Also you can have your monitor shut off after a short period of inactivity to help you conserve battery power.

[Owlbrudder]

Also you can have your monitor shut off after a short period of inactivity

Yes, I have it set to 10 minutes, but that is really too long. If I have not hit a key for 10 minutes, I am away from the machine or asleep (or dead ...). I will ratchet that down to 5 minutes, which gives me plenty of thinking time while I write. I will also set the sleep timeout to 10 minutes, down from 30, for the same reason.

I have set the option to have the disk to spin down when possible, but there does not seem to be a timeout I can set. When I tested all this yesterday, the disk seemed to be spinning the whole time, even when I was doing nothing at all.

Anyway, have a safe and happy Easter and I will get back here with the battery results after my camping trip.

[Owlbrudder]

Well, that was disappointing. After following all the ideas above, I only saw one hour and ten minutes on battery and the disk did not seem to spin down at all.

Anyone wishing to jump in here with suggestions would be very welcome.

[malafide]

First you should tell us what battery you have (6cell, 9cell) and what charge in Wh it can hold. From this we can approximately tell you how long you can expect to run without mains power under what circumstances. With a full 9cell, usually you get 5+ hours.
cat /proc/acpi/battery/BAT0/info

Then you should paste your powertop output in here, so we can tell which parts of your installation sucks up the most juice.

Active measures to prolong runtime are disabling unneeded things so the CPU can stay in C4 sleep state longer (powertop helps with this), dimming the display, lowering WLAN speeds (no need to use 54MBit/s when your Internet only can do 2MBit/s for example), disabling other things like Bluetooth. Undervolting your CPU with linux phc (kernel patches), using the TLP scripts by linrunner, etc.

[comps]

CPU isn't in fact the problem, something like C2D can run at max frequency without really high jump in terms of Watts. The problem is probably (95% of all cases I know of) tied to the graphic card and the linux "noveau" (or 2D "nv") doesn't really help it -- I'm not sure if "yum install nvidia" installed the official driver.

The general suggestion is to use official proprietary Nvidia drivers, they should have automatic power management turned on by default, depending on your card, see http://www.google.com/search?q=thinkwiki+nvidia , there might be some related information. To download a driver, you can use http://www.nvidia.com/object/unix.html .

edit: the disk spindown timeout can be set using hdparm -S, but I don't really recommend it, use hdparm -B 128 instead:

Code: Select all

       -B     Get/set Advanced Power Management feature, if the drive supports
              it.  A  low  value  means aggressive power management and a high
              value means better performance.  Possible  settings  range  from
              values  1  through  127 (which permit spin-down), and values 128
              through 254 (which do not permit spin-down).  The highest degree
              of  power  management  is  attained with a setting of 1, and the
              highest I/O performance with a setting of 254.  A value  of  255
              tells  hdparm to disable Advanced Power Management altogether on
              the drive (not all drives support disabling it, but most do).

... because drive spinup/downs are really more costy than leaving the drive run all the time (5400rpm), especially if you do frequent read/writes (those can be even openoffice autosave writes) - setting writeback flush buffer to higher ratio might help, but the drive has to spin up once in a while anyways and a lot more often when you actually use the disk (accessing directories via some file manager, ...).

[Owlbrudder]

Thank you both very much for replying.

cat /proc/acpi/battery/BAT0/info

Here it is:

Code: Select all

present:                 yes
design capacity:         56160 mWh
last full capacity:      56160 mWh
battery technology:      rechargeable
design voltage:          10800 mV
design capacity warning: 2808 mWh
design capacity low:     200 mWh
cycle count:		  0
capacity granularity 1:  1 mWh
capacity granularity 2:  1 mWh
model number:            42T4566
serial number:            4431
battery type:            LION
OEM info:                SONY

I am not sure how many cells (6 or 9), but both my main and spare batteries are the same. From this, can you give me a ballpark of how long to expect? If I only have a one-hour battery, it is pretty pointless doing kernel rebuilds etc. to try to squeeze more out of it. I am only on battery infrequently, so may find it is all too much trouble for little return.

Then you should paste your powertop output in here

I am currently on mains power, with everything enabled again. I will post my powertop data next time I am on battery

use official proprietary Nvidia drivers

When I boot, I see the nVidia logo - does that mean I have the proprietary driver, even though I used "yum install nvidia"?

drive spinup/downs are really more costy than leaving the drive run all the time

That is interesting. I thought motors were heavy users of electricity and would drain the battery quite quickly. I had my OpenOffice autosave set to 5 minutes; I have just increased that to 10 minutes, so will see if that has any effect.

[comps]

When I boot, I see the nVidia logo - does that mean I have the proprietary driver, even though I used "yum install nvidia"?

Yes, the logo is quite clear indication.

That is interesting. I thought motors were heavy users of electricity and would drain the battery quite quickly. I had my OpenOffice autosave set to 5 minutes; I have just increased that to 10 minutes, so will see if that has any effect.

My 2.5" Samsung HDD motor drains about 0.3-0.5W when idle (but spinning at 5400rpm) and lot more during stopped->idle spinup (around 5.2W for about 1000-1500ms). I've tried to calculate how much power it consumes during one hour, but it seems that the battery current sensor is inaccurate as ****, so much for that.

I've recently tried to set-up laptop-mode-tools on a Ubuntu laptop. It turned out to be a wrong move, ubuntu already has some (unknown for me) ways to switch to lower-power mode when on batteries and laptop-mode-tools actually lowered the battery lifetime from ~4 hours to 1 (I still haven't figured out why). Anyway - the important point is that the hard drive was spinning up and down once a few seconds, which probably sucked a lot of juice.

Simply try disabling HDD spindown and see if it helps. There are many things that may spin it up, including filesystem journal commit, syslog with forced flush, ...

[malafide]

A T61 with Nvidia takes approximately 16W when idle. See http://thinkpad-forum.de/threads/90564- ... post981233
It's a german forum, but I hope everything in that posting is understandable.

So with your battery, you should get around 3h+
It's highly recommended to run powertop and read http://www.lesswatts.org

[pit1337]

In my R61 with Nvidia GPU I can't get below 19.5W (WiFi on, screen @ 30%, powersave CPU governor) = ~3.1h on 9 cell batt = not that bad.