Lower the temperatures on your laptop by undervolting.

xps_laptop_icon_by_freaky_designAnyone that has used a laptop knows how hot they can get. Many commercial products like cooling pads are very popular because they claim to be able to cool down your laptop. Well for one most of them actually don’t work (only a few do). For two, undervolting is a better free solution that will not only lower the temperatures (ranging anywhere from 5-30C) on your laptop by a significant amount but it will help increase battery life and save energy also. The great thing about it is that it does not lower computer performance at all. Undervolting is just a method to lower the amount of excess power that your CPU receives.

I have been undervolting my laptop for a while now and I cross my heart, don’t hope to die, stick a needle in your eye promise you that it works. And it works very well: I decreased temperatures on my CPU by ~10C. Undervolting is actually one of the first things I do after I reformat my laptop. If you are still interested, read on to learn how to undervolt your laptop. However be warned that it can be a long process to get it right. I was one of the lucky ones – I got someone else who had the same laptop as me to provide me with the correct values to use so I did not have to do all of what is going to be mentioned below :D

So who can undervolt? Anyone! Do you need to have specific computer specifications/hardware? No! Ready to learn how to undervolt? Good:

The following guide is the work of flipfire from NotebookReview.com. It is being reprinted here with permission from him. For this guide he used a Santa Rosa T7500 processor on Vista using RMclock v2.35.

Please note that while this method has been tested by many and is proven to work, you are following this guide and doing what it says at your own risk – me, dotTech.org, flipfire, NotebookReview.com, nor anyone else is responsible if anything goes wrong.

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*Advantages of Undervolting
– Cooler CPU (5 to 20c cooler)
– More battery life (15-30mins more)
– Less Fan noise & activity
– Longer overall notebook life
– Eco-Friendly

By reducing the voltage fed to the CPU, it will run much cooler. It will also draw less power from the battery which can give you an extra 10-30+mins battery life depending on the degree of the undervolt. Also a cooler CPU means less fan activity which again points to more battery life and less fan noise. A Cooler CPU could also lead to a cooler GPU if they share the same heatsink/fan. It is common sense that a cooler running notebook will last longer than a warmer/hotter counterpart. Heat is the killer of electronic parts.


– BSOD (Blue Screen of Death)

You will get a BSOD at the very most if the voltages are too low. This is why we do a stability test to make sure we get no BSOD’s. If the voltages are setup properly you shouldn’t get any at all. A BSOD seems to be the only risk for undervolting in my experience. So make sure everything is saved before you do anything. I dont wanna be responsible for any loss or hoo-haa’s.

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You will need to download these programs (Dont install RMclock yet). Click to go on download page

  • RMclock v.2.35 – (CPU clock utility)  Note: A digitally signed/secure driver is required for RMclock to run on 64bit Vista. You can download it from here.
  • ORTHOS CPU Loader – (Used to stress the CPU and test for stability)
  • HWmonitor – (Choose between 32/64bit on top left corner)

(ORTHOS and HWmonitor are standalone programs that do not need to be installed . Just run the .exe files)

1)***Checking Max temps before Undervolt***

Firstly, We need to find out how hot your CPU gets when under load to compare what undervolting can achieve.

  1. Open HWmonitor. It will show the CPU/GPU/HDD’s maximum, minimum and current temps. Today we are only going to be looking at the CPU core temps. I recommend using HWmonitor because its one of the best temp programs and its accurate but others will work too.
  2. Run ORTHOS CPU Loader. This handy program will simulate full cpu load for both cores.
  3. Click on the Start button and let it run for 10mins. Watch the temps shoot up to about 70-90c.
  4. Once its done stressing the CPU for 10mins, stop the program and record the maximum temp.

I managed to get a scorching temperature of 79c.

2) ***Installing and setting up RMclock***

Note: Vista x64 users will need to download the signed 64bit drivers located above to make RMclock work.

  1. Unzip/Install RMclock into your notebook
  2. Run RMclock
  3. Click on the “Advanced CPU Settings” tab. The latest version of RMclock should automatically detect your CPU. If it doesn’t then click on the “Mobile” radio button near the bottom and tick “Apply these settings at startup”. Now hit the Apply button

*AMD users need to tick P-State Transistors for a better undervolt

If it asks you to restart the program, do so. After it has restarted go to the “CPU info” tab. Double check its showing the correct processor you have. On this page you will also see alot of digits moving up and down about your CPU.

3)***Setting up Profile***

Double click on the Profile tab then click on “Performance on Demand” sub-profile.

  • Tick “Use P-State Transitions” for both AC Power and Battery
  • Tick all the index boxes possible, Make sure to scroll down and click the others
  • Click Apply when all done.

Now we head back to the Main Profile page….

  • Change the current profile in the drop down box to “Performance on Demand” for both AC Power and Battery

Make sure all the index boxes are ticked. If you have SuperLFM or IDA i suggest leaving this out for the meantime. See down below later on for what these features do.

  • Untick “Auto Adjust intermediate-states VID” near the bottom and hit the Default button. Your factory voltages should now show up. Click Apply.

4) ***Undervolting***

In the main profile page, you will see different multipliers and voltages.

What are multipliers? Multipliers are incorporated with Intel SpeedStep Technology (see down below for full definition). Instead of the CPU running at full power all the time, multipliers are used to dynamically lower the clock speeds to make the CPU run more efficiently.

The more CPU power you need, the higher the multiplier your CPU will use. The higher the multiplier, the higher the corresponding clock speed will be. The higher the clockspeed, the more voltage it requires to run (vice versa)

  • First, We are going to start lowering the highest multiplier’s voltage which is the 11x multiplier for me.

Most people should be able to lower it by at least .100v to begin with the initial testing then slowly decreasing it from there on

  • Always click Apply so the new voltage can take effect then do the stability test below. Keep doing this everytime you lower the voltage
5) ***Testing Stability*** (make sure all work is saved!)
  1. Open ORTHOS and HWMonitor again. (we will now see how much cooler it is)
  2. Go to the “CPU info” tab of RMclock (you can also watch the temps and stats here).
  3. Set the test type to “Small FFTs – stress cpu” to concentrate the test to the cpu.
  4. Run ORTHOS stress test for 45mins or more

– If it doesn’t crash when the stability test is done then you can go lower. I suggest lowering by .025v at a time till it BSOD or gives a warning error.

*If you get a bluescreen – then you have reached your limit and the voltage is too low. Once it restarts from the BSOD, it should revert to the last stable voltages. Keep a record of the good/bad voltages on paper.

*If you get a warning or hardware error from ORTHOS – Your voltage is also too low. Raise your voltage and try again.

-Once you have found your unstable voltage, i suggest raising the voltage up by 2 steps. This will put a safe margin away from your unstable voltage to ensure stability

**Its normal to get a BSOD or error at some point so dont freak out. It wont do any hardware damage.

**Most people are able to achieve .150v to .250v less than their default voltages for the highest multiplier. Again, it all depends on your processors tolerances.

6) ***Results***

After several changes and stability tests i was able to lower it to 1.100v that’s .150 volts less than my standard voltage (1.250v). My undervolt isn’t as great compared to how low others can achieve but it has made a significant difference.

My max temps before undervolting was a scorching 79c now it is only 67c! That’s a big 12c shaved off at the cost of nothing.

I cannot accurately calculate how much extra battery life this will give cause of too many variables. I can only estimate about 15-25mins by perception as i havent got proper benchmarking programs and monitors. From what other users have posted, they saw an average of 10watt difference which should reduce the strain on your hot power adapters.

When you have found your optimum voltage settings, I suggest doing a further 3 hour stress test (when you have spare time) to make sure it is 100% stable.

Once you have made sure this voltage stable, you can now choose to make these settings run at startup:

Go to the Main Profile page > On the drop down box for startup choose “Performance on Demand” > Hit Apply

Now go to Settings page > Tick “Start Minimized in Windows Tray” and “Run at windows startup” > Hit Apply

To show your CPU temps in the Taskbar/System Tray > Right click the RMclock wheel icon and click “Show CPU Temperature”

TA-DA! Enjoy! Watch your notebook run significantly cooler

7) ***Lowering and Testing Other Multipliers voltages***

To make the most out of Undervolting, you can also lower the other multipliers to its optimum voltages. So far we have only set and tested the max multiplier. The lower the multiplier #, the less voltage is needs.

To do the stability test on the other multipliers we will need to disable the highest multiplier by Unticking it in the Main Profile page (11x multiplier for me) then clicking Apply. This will stop the CPU from using this multiplier meaning the 10x multiplier meaning this is the highest speed your CPU will reach. Each multiplier corresponds to a clock speed 11x is 2.2ghz, 10x is 2ghz, 9x is 1.8 (for my CPU of course)

Now you know the drill…

  1. Lower the voltages slowly
  2. Run ORTHOS test for 45mins
  3. Double check in CPU Info page or CPU-z that its stressing and maxing out at the correct multiplier
  4. Find the optimum voltage
  5. Move on to the next multiplier by unticking the higher multiplier profile page then back to step 1

You do not need to test the lowest multiplier (idle) because we cant change/never changed the voltage. This voltage will always set at a stable voltage

Its a time consuming process getting the optimum stable voltages for every multiplier but it pays off in the end.

Note: After your done, make sure you re-tick the multiplier boxes in the “Main Profile” page then “Performance on Demand” sub-profile page, If you dont your CPU will be majorly handicapped

The lower the multiplier #, the more sensitive the voltage is to a BSOD! Most BSOD’s from undervolting are usually because of unstable lower multipliers. For first time undervolter’s i suggest leaving a small voltage margin from your unstable voltages.

Quicker Alternative: If you dont have to time to stability test every multiplier there is another way. Ticking the “Auto-adjust Intermediate States” box will fill in all the multipliers in between your Idle (6x) to your highest multiplier accordingly. It seems to work well for at most cases but theres no guarantee that all the multpliers are 100% stable, since it just fills it in mathematically. It seems to work fine for most people though.

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That is about it. Let me know if you guys have any problems undervolting – I will try to help to the best of my ability or I will refer you to someone who can help.

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  • onos

    my hp630, don’t show the advanced cpu setting, what will i do???????????? pls sm1 help

  • grats


    If you use BIOS it has nothing to do with operating system & will not matter which one you’re using

  • shiva

    Does it really work…???….. Or again just a crap…???. And will it affect my laptop performance….. Its dell vostro 1400 core 2 duo… Centrino

  • Mark

    HP tx1019au, OS: VHP 32, AMD Turion 64 X2 TL-60, 2.0GHz
    I am attempting to undervolt for the first time.

    Recently had the Nvideo chipset removed, cleaned and re-soldered by a tech.
    previously inop the last 8 months, as I was so frustrated with the continual problems.
    I assume when it was opened to do the reflow work the fan was cleaned.
    I will be opening it up soon to check and perform the heat sync work required by these crappy HP’s.
    First things first.
    I was unable to achieve any improvement with the undervolt procedure, specifically the 10x or 4x multipliers.

    Comp. Flat on table:
    Heat at rest: CPUID HW Monitor: Core 0: avr: 64, Core 1: avr: 52
    Rightmark Core temp: 64c

    My procedure according to what I understand to be correct from the guide:
    1. Selected: use P-state transitors (PST)
    2. All Indexs selected\applied
    3. FID: 4.0x \ reduced from 1.1250V too 1.10V\auto-select deselected\applied I first tried to reduce the 10x multiplier but BSOD after 10 seconds durng Torture test)
    4. Prime95 Torture Test (small FFT’s) run

    Result: BSOD after :10 sec

    from what I understand I am unable to undervolt this comp. At all!
    Any help would be appreciated, I have >US$ 3k sunk into this machine.
    It has spent >½ it’s life (new June, 07) broken down.

  • Thx for info ;)

  • Amir

    Any idea how I can accomplish this in Linux?

  • Smart3go

    It seems that RMclock does not show “Advanced CPU Settings” tab for those CPU’s that it does not recognize. In my case I have AMD Turion(tm) X2 Dual-Core Mobile RM-70, and although “http://cpu.rightmark.org/products/rmclock.shtml” states under “Supported platforms: CPU” that “AMD K7 (Athlon/XP/MP, Duron, Sempron) and K8 (Athlon 64/FX/X2, Opteron, Dual-Core Opteron, Sempron, Turion 64/X2) family processors.” are supported I had no luck.

    Acer is not the only manufacturer who is infamous of overheating. In fact I have tx2000 and the AMD CPU reaches 100 degree C easily when the fan/heat sink is clogged. My wife’s hp DV# (I forgot its number :) ) also heats up but on HDD side. It has to be bad thermal design/bad component design per model as my old Acer Aspire was the best in that regard.
    If you know someone in hp tell them to hire me as I got better design ideas to eradicate the heating problems from the source, and other ideas as I’m “Smart3go” ;)

  • ebrahim

    my laptop cannot run ORTHOS for more than 4 min
    the temp exceed 100 than shutdown.

    a always use powersave mode in power plans, to try keep it run long time without shutdown.

    my laptop hp pavilion dv6000 with amd turion 64 x2 mobile tl-60

  • AdmiralDeath

    @Ashraf: I also have the problem of the advanced CPU settings option not showing up.

    Has anyone discovered a solution for this?

  • Ashraf

    @Markus: Ah, glad to hear that. The only reason I mentioned Acer is because Acers are known to overheat.

    @Asevete: You are welcome! Although, I cannot take credit for writing this up.

    @Samth: Whoops, my bad.

  • Samth

    Nope. I have a HP Touchsmart TX2.

  • Asevete


    Excuse by bad english, your article is excellent!

    I have take the second option (auto adjust intermediate states VIDS) : I’m able to lower it to 1.150v that’s .11250 volts less than my standard voltage (1.2625v) (FID 11x ; DualCore Intel at 1828Mhz)

    My max temps before undervolting was a scorching 65c now it is only 39c if the computer don’t work (just boot and wait)… ad only 47c when surf on the Internet.

    Very good! Thank you!

  • Markus


    I have a acer 8735G. Bought in december 2009. It started now during playing GTA 4 to turn off after 1.5 hours.I disconnected powersupply and battery. I removed on the bottom the cover of the fan. You see then in the rear the heat sink and ventilator slots. I cleaned it out with compressed air. Waited 15 min. Now its working again as before.

  • Ashraf

    @Samth: I am going to go out on a limb and guess you have an Acer.

  • Ashraf

    @Markus: Yeah, but telling people to clean out their heatsink is a lot more intimidating than telling people to clean out the fan.

  • Markus


    It doesnt matter if canned or compressed air.

    If you use canned air its mixed with some gases under pressure in the can. If you spray to long it builds up a freeze on the surface. If it vaporates some moisture will be there. So you have to be carefull with canned air.

  • Markus


    The dust on the heatsink / radiator works as insulation. the heatsink is often connected to the graphiccard and cpu so it has a lot of heat to spread. Its also important to clean it.

  • Samth

    @Locutus: I got 100ºC last summer.

  • Ashraf

    @Markus: Excellent advice. Cleaning the dust from the inside of your computer – particularly on the fan – is one of the best ways to keep temps low(er).

  • Ashraf

    @Dru: What is the difference between the two? They sound the same to me, LMAO!

    @Dru: Umm I have been outa the laptop cooler game for a while, but as far as I remember, Zalman and NZXT make some of the best ones. They are, however, expensive compared to the competition.

    @Tommy: If you get a BSOD that means your voltages are too low. Raise them.

  • Tommy

    Just wondering…you mentioned there is always a risk of BSOD. Have you covered this before in another article or will you in the future how to deal with the BSOD?

  • Tommy

    @Dru: @Dru:
    Just wondering…you mentioned there is always a risk of BSOD. Have you covered this before in another article or will you in the future?

  • Dru

    Ashraf says, “Many commercial products like cooling pads are very popular because they claim to be able to cool down your laptop. Well for one most of them actually don’t work (only a few do).” Which cooling pads work?

  • Dru

    Really that important to use canned air instead of air compressor?

  • Markus

    Most laptop have a copper radiotor. The fan sucks the air through it. After 1.5 years the cooling system gets clogged with dust. The dust will work as insulation. If you play games the graphiccard and cpu heats the system up and the after some time it just turns off because its too hot. Cleaning the radiator and the fan with compressed air will clean the dust out and keep the temperature low again. Better do it outside its a lot dust and disconnect powersupply and battery. And if you use canned air wait 15 minutes until you connect the battery and powersupply again because of moisture.


  • Student26

    had to get the driver because the one that came with the download was unsigned

  • Beat 98C!

  • HellNoire

    Just wanted to say thanks. There were a few rough spots I found in trying to understand this, but I was able to lower voltage and temperature by about 20 degrees on idle (only 6 on full load) and by almost a full volt.

  • mukhi

    why the hell RM clock is not showing up advanced CPU settings? looks like it installed correctly! now, i can’t proceed…

  • Mike

    I am right now undervolting my laptop. First off, thanks a million for this article. My “gaming” laptop might actually be able to “game” now. I am a little unclear though on what I must do with the SuperLFM and IDA boxes that I unchecked at the beginning of this process. Should I just re-check them or do I need to adjust those numbers as well? The IDA numbers will seem very high now that everything else has been adjusted.

  • Mike

    This is a great help. Thanks a lot for it.

  • Argh. I got 97 degrees C with no undervolting, but then I ran the different test after undervolting and got 102 degrees C. Then my laptop shut down and wouldn’t start for 5 minutes because it knew it was too hot.

  • Yes you only need RMClock after you find out your proper voltages.

  • Hi
    Great website
    So I only need the RM program out of three after doing this?

  • Frank

    I hate people/companies pretending to know my needs better than I…

    I’ll have to wait for NHC to support DualCores. At least the SingleCore version starts at 0.7 volts (which freezes the machine, but my 15″ runs since 4 years stable at 0.796V (600 MHz) and 0.812V (800 MHz)).

  • That question has been asked a lot and I think the general consensus was (up until I stopped following the topic) is that the .95V minimum limit is there for safety. In other words, the lowest you want to go. Of course this was like 6 months back so things may have changed by now.

  • Frank

    BTW. Does anyone know how to lower the voltage using RMClock /below/ the 0.9 volts it does offer?
    I am sure my processor runs with less too, and it saved valuable battery life (I had 5 hours with my 15″ 1.7GHz Centrino, now I have 2.5 h with my new DualCore 17″ thingy – though the capacity of the battery raised from 44 to 58 mWh).

  • Frank

    in general you can divide between 1st and 2nd generation “CPU coolers”:
    1st generation (like CPU idle) only stop the CPU from working (do for instance a socalled HALT command) and save a little power by that.
    Not very effective but at the times of Pentium IV (and the chipsets at that time) you couln’t do much more.
    2nd generation does real power management by lowering the voltage (and so the power consumption, see above) using the spread betweenn specification and real need of the processors (that’s why the voltage a processor needs to work flawless can pretty much differ between 2 CPUs of the same make).

    I haven’t touched CPUidle since years, but you can have a look yourself: If your program of choice has a “voltage management” it’s worth trying. If not – not.

  • Kite,

    I have no used CPU Eat n Cool or cpuIDLE. However I just googled cpuIDLE and it seems that it is a power management program. I don’t think cpuIDLE will play well with RMClock.

  • Kite


    The undervolting is a really good idea. My Dell Inspiron 700M was hitting 88C (THRC) and 46C (hard disk) just for regular web surfing and a lot of background processes running as a tech junkie. I even went so far as to use Ace cold compress to bring down the temperature – low tech but highly effective.

    Anyway, I found that the default power saving profile brought down temperatures by 20+C. I am unable to use ORTHOs to run a stress test to test stability since it will not startup. Also could not get the CPU temperature even after flashing the bios with the latest update from Dell. Hence not inclined to experiment further here, but seems pretty stable.

    I found that using a fan utility (I8kfanGUI – compatible only with Dell Inspiron and listed models) at high speed also helped to keep the temperature down a further 5C to 10C. Will be buying an external cooling fan base for home use, and leaving the system fan for when I’m outside.

    I next tried CPU Eat n Cool,a freeware to manage the CPU — felt that it only increased the CPU load without significant improvement. Someone suggested cpuIDLE, which is supposed to be a more effective software for CPU management for XP and Vista, albeit not free. I wonder whether anyone has tried out the CPU management software?

  • What 4, 5, 6, and 7? Are you talking about multipliers? Just don’t do the SuperFLM and IDA ones – you need to do the rest.

  • Do we skip 4, 5, 6, and 7?

  • Everything is in the guide above >.>’

  • How do I check to see that it is working?
    What are the steps for using auto adjust?

  • xje4bv

    This is great for my laptop with overheating issues. once fried my motherboard. Good thing it was still on warranty. Thanks a lot.

  • You do have to because you at least need to set one multiplier to a value that works for you to properly have the program auto adjust the rest of them.

    It will probably work best if you have the lower multiplier and highest multiplier set to what works for you then use auto adjust.

  • Oh and one more question — If we plan on using the “Auto-adjust Intermediate States” feature, do we need to download all three programs?

  • Oh, I see. :P Thanks for all that you do. I unsubscribed to GiveAwayoftheDay and subscribed to your website since I tend to check it first ;)

  • Oh, haha. He was talking about Notebook Control Hardware which is a different program :)

  • Frank said:

    You Ashraf also could have a talk to them to informm you when the DualCore version of the program is available so you could post it here.

    Did I misunderstand that?

  • Liam,

    I don’t understand. Where did you hear that? RMClock works on dual core just fine – there is no need for ‘optimization’. Me and the person who wrote the guide above use RMClock on dual core. Thousands of people use it on dual core. Can you please explain what you mean/are thinking?

  • But if there’s a version optimized for dual core in the works, I’ll wait for that.

  • Liam,

    This works on dual core o_o. I use it on dual core.

  • Oh, thanks for letting us know. I’ll wait for the dual core version ;)

  • samuel lightfoot

    Just plain old physics, Frank said. Worked well on my Acer Aspire. (Turion X64x2.)

  • Frank

    How does it work? Actually it’s plain physics: You can see the CPU as a resistor and use the formulas I = U*R and P = U*I which combined are P = U*U*R.
    So the power consumed raises (or lowers) by sqare with the higher or lower voltage you give to the CPU. That’s why small changes lead to huge differences.

    BTW: For people with NO DualCore CPUs there also is the tool Notebook Hardware Control which has lots more features and is easier to handle than RMClock. See at http://www.pbus-167.com/nhc/nhc.htm

    You Ashraf also could have a talk to them to informm you when the DualCore version of the program is available so you could post it here.


  • Basically you lower the amount of power going to your CPU. Since there is less power going to your CPU it will generate less heat. The power that is lowered is excess power so it does not effect your performance at all.

    It is actually a lot easier then it looks.

  • Interesting. In simple English, how does this work? ;)