For CPU power savings, I recommend RMClock. http://cpu.rightmark.org/products/rmclock.shtml. Good for undervolting and controlling CPU states to much finer detail than you find anywhere else, though it takes a little work to get the hang of it. I have an Toshiba M200 Tablet, and I was able to add a solid 30 minutes to my battery life by tuning the settings.
What we need is a turbo button on laptops. We can set the CPU usage to 25% or 50% then when we need to do something big just press the turbo button and get 100% cpu instead of having to change the settings.
Wow, I never realized there was such a difference in the power consumption of a CPU at idle and maximum power draw.
A comparison between the power consumption of the Dell Inspiron 300M laptop and the the Dell XPS M1330 would have been interesting.
Just so you know, you don’t have to manually switch to power savers mode every time you unplug your laptop.
Just click on the battery icon, go to “more power options” and then click on advanced preferences (or something like that, I’m not on my laptop right now). Over there you’ll be able to set custom settings on what you want your laptop to do when its plugged into an outlet or on battery power. I’ve got mine setup to automatically dim the LED and go down to 50% CPU whenever I unplug the power.
You can even change the settings so that actions like closing the laptop lid or pressing the power button do different actions (Shutdown, Hibernate, Sleep, or Nothing) depending on whether you’re running off the battery or not.
Best of all, you don’t have to fiddle with the settings every time you want to take your laptop with you 
What we need is a turbo button on laptops. We can set the CPU usage
to 25% or 50% then when we need to do something big just press the
turbo button and get 100% cpu instead of having to change the
settings.
It’s basically three clicks away:
double-click the battery icon
click “High Performance”
Done
To switch back, double-click the battery icon again and select the previous mode (Balanced or Battery Saver).
My Balanced mode (the mode I always use) is slightly tweaked (to reduce the performance throttles), but for the most part I don’t have trouble with my laptop’s power use on battery. I guess if my laptop were smaller (ie small enough to actually use on a plane) I’d run into these issues more, but I prefer to use hand-held game systems and books while on the plane, and if I need to make a note for myself or write an email (to send from the airport or hotel), I’ll use my phone.
Thanks for the article. I want to use a laptop as a deck with 12 hour battery life, so every watt counts.
I won’t need the graphics or networking subsytems on /at all/ though, so I hope I can turn PCI devices completely off.
SSD’s should get much more efficient over the coming years.
…but before I go blowing hundreds of dollars on modular bay batteries and SSD’s, I’d like to know this:
How exactly did you get per-component wattages? Assumptions? ACPI? I want real time measurement, by component, of power usage of my laptop while on battery.
BradC, the video will be decoded by the GPU/CPU regardless of the source, computer dvd drives have no decoding capabilities, much less laptop ones.
Your best best will always be to rip the dvd to the hard drive.
A quick search tells me that in the United States, using any software that can bypass the security restrictions of a DVD is illegal, even if you are only using it for personal use.
Bummer.
BradC on April 14, 2008 08:17 AM
While this is technically true, this shouldn’t be an issue since they won’t know AND further reading of US laws and Fair Use, will show that despite the recently made law(s), the MPAA would have a very difficult time trying to sue due to fair use (in this instance) trumping said laws. While distributing would be very problematical for you if caught, for your own use (when you also own the dvd), well then the MPAA would likely loose outright.
Still, it would be a gamble if you are going to a MPAA conference with your recently ripped dvd files on your laptop… =)
I just formulated a test of my own to figure out ideal power settings. Record your start time right when you unplug. Use your laptop regularly as you normally would under the Balanced power setting until you hit 50% battery. Record your cpu mem and uptime/current time. Then switch to Power Saver and record what your final stats were when the remainder of the battery drained under the same load. Compare the differences in times between 100-50% and 50-0% Obviously the second time should be longer, but exactly how much longer will tell you if it’s worth it. Multiply by 2 then you have a somewhat accurate estimate of what your power needs are and what you stand to gain from using lower power settings.
Surely, your wattage numbers are of the WHOLE laptop, not individual components? Careful when writing How much power does the hard drive use?, I think what you really meant to say is How much power does the laptop use when hard drive is a) idle b) defragmenting.
Right?
Because the Core 2 Duo CPU has a TDP of 35 watts (i.e. it consumes 35 watts at most, most if not all of this energy becomes heat, as far as I understand), however it appears you are saying it consumes 63 watts doing to Prime95 torture tests. Something is wrong with those tests, sampling, or with you formulation. Please clarify.
could you please check our internet
Instead of mucking around with power settings on your laptop, why not buy a PC that uses only 8 Watts of power? These little PC’s can be mounted on a LCD and run from a solar pack, that would become your 19 laptop…run on free solar 
You can read more about them and watch a demo at:
aleutia.com/products/demo.html
http://www.aleutia.com/products/demo.html
Bill from Aus’
Great write up.
My laptop is lucky to get 30 Minutes…
Time to buy a new battery i guess.
Our IT unit wants staff members to log off their desktop computers on evenings and weekends rather than put them into sleep mode or shut down completely. I’ve been able to find a comparison of power use between on, sleep, and shut down, but does anyone know how much power is being used if you choose the “log off” option in XP?