Undervolting a laptop article

Delph1 · Guest

Laptops often comes with two Achilles heals, heat and limited battery time. There are, if not cures, at least remedies to make them less obvious. The technology used is called undervolting and even if reducing the voltage would be a more precise description the name is still pretty easy to get. By lowering the voltage to the processor you can not only drastically lower the heat dissipation, but also increase the battery time significantly. There are, believe it or not, no downsides with this method, if you do it right. Therefore our new laptop writer Fredrik Andersson has written a guide that in detail shows how you to lower the voltage in a safe manner. The results achieved by Fredrik with his computer was 18% lower temperature and a 20% reduced power consumption. Read on in our latest article here at NordicHardware.

"Because CPUs are mass-produced, the voltage is set to a stable level that will suit all samples of that particular CPU. Everything from CPUs with �Friday Afternoon Syndrome� to real overclockers. There are lots of CPUs on the market that can be run at a lower voltage then what they are specified to. Especially the kind of low power consuming CPUs found in laptops. You'll be surprised when you see the results of undervolting your CPU."

:: Read on here at NordicHardware

Delph1 · Posted: Mon Jan 23, 2006 7:22 pm Post subject:

If you're using a Pentium M you can achieve even better results. We compiled a small table with users results, I'll see if I can get my hands on it.

//Andreas
_________________
"I'm sort of a postmodern vegetarian, I eat meat ironically"
"You are our Swedish superhero Wink

"

Forget everything, knowledge is your enemy, it's only going to make you second-guess yourself."

fackamato · Posted: Mon Jan 23, 2006 8:05 pm Post subject:

Great article Smile

. Too bad laptops aren't for me... Smile

_________________
Open Source > *

magicman · Posted: Mon Jan 23, 2006 8:36 pm Post subject:

Balder · Posted: Mon Jan 23, 2006 9:58 pm Post subject:

Hey guys. I'm the one who wrote the guide. And unfortunally i have lost the table that i haved that showed some of the results who well a Pentium M CPU undervolted. But i can tell you one thing that the P M is the best CPU today to undervolt. With this guide you can lower your voltage with approximily 30% on both clock speeds.
_________________
Acer Aspire 5021WLMi

magicman · Posted: Mon Jan 23, 2006 10:00 pm Post subject:

well that makes me extra sad... cause I'm the guy's not sellin it now... atleast not yet... Sad

Delph1 · Posted: Tue Jan 24, 2006 12:47 am Post subject:

I've updated the article with Fahrenheit values and made it a bit more obvious the other values where in Celsius to help our American friends. Wink

//Andreas
_________________
"I'm sort of a postmodern vegetarian, I eat meat ironically"
"You are our Swedish superhero Wink

"

Forget everything, knowledge is your enemy, it's only going to make you second-guess yourself."

Erucolindon · Member Joined: 24 Jan 2006 Posts: 4

Hey guys, I just read the article and am quite interested in trying this. Im on a dell, intel celeron. I installed rm 2.0 and it doesnt give me any info on VID, just N/A, and it doesnt give me the option to set anything manually. Is there something I'm missing, or is this not possible for me to do?

I want to try this, as my laptop overheats when sitting on my desk. I have to keep it elevated a couple inches for the fan to have air to circulate. It took me a while to figure out why it was just shutting off or would be off when I come home. I think underclocking could solve this problem or at least lessen it a bit.

Thanks
-Chris

n3hat · Member Joined: 24 Jan 2006 Posts: 1

The heat savings in the article is understated. Unless the machine uses a heat pump or Peltier junction for cooling, it cannot be cooled below the ambient temperature. Assuming 23C ambient, 78C is 55 degrees above ambient. A reduction of CPU temperature from 78C to 64C is 25% of this 55 degree rise, not 18% as stated. This is in line with the 21% reduction of power consumption, since some of the power is consumed in circuits that do not run at CPU clock speed.

Great article, thanks.

Delph1

Delph1 · Posted: Tue Jan 24, 2006 1:01 am Post subject: Re: Undervolting a Laptop article

Erucolindon · Member Joined: 24 Jan 2006 Posts: 4

Balder

Fluidity · Member Joined: 24 Jan 2006 Posts: 3 Location: London, UK

Hi guys,

This all looks very interesting indeed. My laptop has been overheating like crazy due to a heatsink problem and powering off i presume to protect it from frying itself. One of the screws holding the heat sink on had its heat mashed so I couldn't unscrew it and I've only just managed to drill it out, replace the compound between the processor and the heat sink and now its running a lot quiter, cooler and not shutting the power off all the time. However its still a P4 in a laptop chassis and still does get mighty hot so this sounds very interesting to perhaps sort things out a little more.

I'll let you know how it goes. ALso if anyone else has ever had the problem of a scrwew stuck in their motherboard that they can't get out as the head is gone, I recommend trying the micro grabit as it only cost me �10 and worked like a dream.

I'll be back to let you know how the undervolting goes,

Fluidity.

fackamato

Delph1 · Posted: Tue Jan 24, 2006 7:43 pm Post subject:

Both the Pentium 4 M and the Althon 64 Mobile are really far from suitable to be used inside these small laptops, even though the latter is pretty ok compared to the Prescott at least, they still get too hot (I'm guessing you're running a Northwood core though).

The whole desktop replacement category is a bit of a mystery to me, I want my lappies small and preferably ultra-portable, but then again not everyone is like me Wink

//Andreas
_________________
"I'm sort of a postmodern vegetarian, I eat meat ironically"
"You are our Swedish superhero Wink

"

Forget everything, knowledge is your enemy, it's only going to make you second-guess yourself."

Erucolindon · Member Joined: 24 Jan 2006 Posts: 4

Delph1 · Posted: Tue Jan 24, 2006 9:50 pm Post subject:

Erucolindon · Member Joined: 24 Jan 2006 Posts: 4

How goes the search for software to undervolt my Celeron?

Thanks,
Chris

Delph1 · Posted: Thu Jan 26, 2006 8:08 am Post subject:

No luck on my behalf Sad

//Andreas
_________________
"I'm sort of a postmodern vegetarian, I eat meat ironically"
"You are our Swedish superhero Wink

"

Forget everything, knowledge is your enemy, it's only going to make you second-guess yourself."

Fluidity · Member Joined: 24 Jan 2006 Posts: 3 Location: London, UK

Thanks for the welcome!

Still waiting till this weekend to try the undervolting but it should prove interesting, have all the programs downloaded and installed ready, just need to find a decent length of time to do it in!

In answer to the question, a micro grabit is a tool a bit like a drill bit. One end is effectively a drill bit which you use to vreat a v shaped cavity in the screw head and down a little bit into the length of the screw. YOu place this in a power drill, cut out the small pieces of metal (I used a vacuum sucking as i did it to make sure i didn't end up with any little piece of scre head connecting contacts and shorting things out when I turned everything back on). Then once you have made the cut in to the screw, oyu take it out the drill and put it in the other way around which has a shape similar to the cut you just made but with a slight threat on it. You screw that in slowly using the drill and it locks into the scre head, then reverse the drill direction and it unscrew locked to the drill bit. Well that's the theory anyway, took me a few goes to get it to work but it did the trick. Anyway, hope that wasn't too off topic for this thread but maybe someone else out there might have the same problem as I did and that might help! The site about it is:

http://www.boa-uk.com/boa_grabit.html

Anyway, I'l be back again after undervolting as that should be a little more on topic!

Fluidity

Fluidity · Member Joined: 24 Jan 2006 Posts: 3 Location: London, UK

Unfortunately it doesn't look like it works on a Pentium 4, Northwood core as the VID's are N/A as with the celeron chip mentioned above. I wonder if this will ever be supported or if it just isn't possible for some reason.

Fluidity.

magicman · Posted: Sat Jan 28, 2006 9:25 pm Post subject:

I just got mmy P4 3.0 laptop last night... I tried this progam, and then it dawned on me... the P4 has locked multipliers, and it doesn't do the speed stepping... mine is constantly running at 3.0Ghz.
_________________
E6600 @ 3800Mhz | EVGA 680i | 2GB DDR2 PC8500 @ 550Mhz | 7800GT |Silverstone Zeus 750W| DD TDX 120mm waterloop

magicman · Posted: Mon Jan 30, 2006 7:27 pm Post subject:

havin some issues with getting my hands on mobile meter... the site is FUBAR... even translated, the download page is broken...

Delph, you should add it to the archive...
_________________
E6600 @ 3800Mhz | EVGA 680i | 2GB DDR2 PC8500 @ 550Mhz | 7800GT |Silverstone Zeus 750W| DD TDX 120mm waterloop

Delph1 · Posted: Mon Jan 30, 2006 7:59 pm Post subject: