Fast Forward: Underclocking to Save Energy



+ Add a Comment


As everyone said, this is more or less useful for the mobile environment, where mobility means how long you can stay off the grid, not how much performance you can get out of a machine.

Well, of course, it also helps if the processor can still perform its tasks within a reasonable time.



I see a lot of comments angling at "who cares about saving energy rarrrrr."  I think that's missing the point--at least for mobile devices.  Battery life on modern devices could be better, and this will help us get there.

Also, extreme power gating on desktop CPUs could supercharge Intel's already impressive Turbo technology.



I both undervolt AND underclock my smartphone.  With a simple undervolt of 50-75mv and an underclock from 1ghz down to 700mhz, you can easilly achieve 8 hrs of extra battery life.  It makes all the difference in the world on long work days, out on the road without the ability to charge.  I can also honestly say that I am unable to differentiate any change in speed with the changes applied.



I agree that the little savings in power is not worth the massive effort. But there are 3 HUGE benefits:

1) Battery life could increase when doing non-intensive things, like browsing the web or reading mail. Batterys could last almost twice as long!

2) Solar powered cell-phone / tablet / laptop? If it won't use more energy than a solar panel can produce, you could use it all day with little or no battery drain, and even have a charged battery for after-dark use.

3) PC's and Datacenters generate lots of HEAT. Lower powered cpu's make less heat, and require less cooling. Media center PC's could be smaller and even left in closets with minimal venting. Servers wouldn't need as many air conditioners. Desktops won't heat up the room when not doing heavy use.




what are we talking about 50 cents per month for the average user?



I sometimes underclock my desktop CPU to 60% (.975v @ 880MHz) via a custom power saving plan in Windows 7 when I plan on leaving my PC for 4-6 hours or more if I'm seeding torrents or doing other tasks that don't require much CPU power. For the most part the dynamic clock of contemporary CPUs is good enough for everyday use.



im 14 I dont really care about my processor using 124 watts. but it does add up and cost I know. But Im never going to underclock my cpu to save on power



I would never underclock, but undervolting can still offer the same benefits without performance lost, basically inverse overclocking


I was able to take a laptop of mine down from .9 volts to .725 volts, pretty good savints



You'll never convince me to underclock my computer to save energy.  Servers, sure.  Desktop, hell to the freaking no.  I'd be willing to double my power bill if it meant a 50% speed boost.



I'm not sure everyone would be willing to double the power bill (depending on where they live).


I'm curious, how much different is underclocking then overclocking a CPU?

Log in to MaximumPC directly or log in using Facebook

Forgot your username or password?
Click here for help.

Login with Facebook
Log in using Facebook to share comments and articles easily with your Facebook feed.