[Tfug] battery life, power management and windows vs linux

[Jeremy D Rogers]

On 3/21/07, Sean Warburton <hl2addict at gmail.com> wrote:
> Plug it in (or a solar panel...we are in Arizona, after all...) :) How about
> the screen? Are there any options for toning down the brightness? Also, what

Well, as I mentioned, the brightness is set at the same level in both
OS's. See, my quest is not so much about getting 30 minutes more
battery life, but more about getting the same battery performance in
linux as in windows.

> about lowering the refresh rate? (may not be much, but what if?) Also, you

That's interesting.. I thought laptop LCD screens had fixed refresh
rates. After all, we're not sweeping electron beams here. I am
dropping the clock rate of the video card to its lowest setting, which
does seem to boost battery life a little.

> may consider resolution (less pixels=less work for the computer to do,

The res is the same as in Win.

> right?) Also, UNDERCLOCKING!?!?!! AAAHH. Thats against my religion...If you
> are going to underclock for an extra 30 minutes, why not save $$$ and get a
> 1 GHz comp. The Pentium 3 class of processors goes up to 1 GHz, you know...

Well, that is the beauty of mobile processor frequency scaling. I get
both. I have a 1 GHz processor sitting there when I'm checking email,
but when I start my data analysis and need the power, suddenly my
clock speed doubles until the calculation is through. All that
automatically, I can't complain.

>        Also, do you have one of those "12 cell" batteries, or whatever the
> best type is? That is supposed to give you a substantial time increase, but
> may cost a bit. But with the best type of battery, you can get increased
> runtime, and possibly run it at the 2 GHz setting. Try two batteries, even.

Again, the battery life is fine, and if I'm on long flights, I may
well think about getting a second battery, but the quest here is to
find out why windows seems capable of eeking out an extra hour with
the same hardware and same (as far as I can see) settings.

Thanks for the thoughts though. I may have to read up on refresh rates
and see if that is really fixed for an LCD.

>        Hope that helps,
>             Sean
> On 3/20/07, Jeremy D Rogers <jdrogers at northwestern.edu> wrote:
> >
> > Well, I finally have my shiny new thinkpad t60 and I love it. Fantastic.
> > <excuses> Unifortunately I will  need to use some windows-only optics
> > software, so unlike my last laptop, I left windows installed on it and
> > made it dual boot.</excuses>
> >
> > Now as I've been tweaking things over the past week, I noticed that
> > the battery reports around 5 hours under windows and only 3.5 hours
> > under linux. So begins my quest. I know many things can suck power, so
> > I think I took care of all the usual culprits. Here is a list of what
> > I have working in linux:
> > - cpu freqency is scaling using ondemand governer (down to 1GHz from 2GHz)
> > - disks are spinning down using laptop-mode
> > - wireless radio and bluetooth are off (modules unlaoded and kill switch
> > on)
> >
> > I did some reading up and I found out that the ati cards like my X1300
> > require the binarry fglrx driver to control the GPU clock scaling.
> > Pity I have can't use opensource, but it did help me get from 3.5 up
> > to around 4 hours on battery:
> > - gpu frequency scaled down and in low voltage mode
> >
> > Now I'm stuck. Things I've tried that haven't helped much:
> > - unloaded usb modules
> > - unloaded pcmcia/cardbus modules (or issued cardctl eject/suspend)
> > - unloaded modules or tried physically removing unltrabay dvd drive
> > - unloaded sound modules
> >
> > The ultrabay actually seemed to help a little, but overall none of the
> > above gained much over 4 hours.
> >
> > I welcome any and all suggestions.
> > JDR
> >
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>
>
>
> --
> Windows Vista Ultimate beta (build 5600)
> Ununtu 6.10 (dual boot)
> ASUS P5N32-SLI Premium
> Intel Core 2 Duo 6600
> dual eVGA 7900 GT OCs (full x16 SLI)
> 1 gig DDR2 PC2-6400 (OCd to 866MHz)
> custom Liquid cooling :)
> four 17" CRTs (uber widescreen)
> 7.1 surround sound (296 watts)
> 160 gig HDs in RAID 1 setup
> one happy gamer
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