Unlike many external cooling tweaks, undervolting uses software to lower the voltage of your CPU. By doing so, it keeps your CPU cooler, and increases power efficiency meaning you get more out of your battery. In this guide, we will go in depth on what undervolting is, how much you can achieve with it, and how to actually undervolt your notebook.

What is Undervolting?

Undervolting is the process in which excess voltage is reduced utilizing software. Individual processor chips are manufactured in an unequal manner; as a result each chip has a different voltage tolerance. Manufacturers’ such as Intel, or AMD tunes each chip to a fully stable, relatively high standard voltage.

Undervolting takes advantage of the high standard voltage by reducing it, thus reducing the operating temperature of a processor anywhere from 5C to 30C. The reduced voltage reduces the power draw by the processor which leads to the temperature drop. A reduced power draw also means you get more out of your battery. In fact, undervolting can lead to 15 minutes or more of additional spare battery time.

It is not to be mistaken for underclocking; Underclocking is the deliberate reduction of the speed of a CPU, often to reduce power consumption. Underclocking leads to a loss in performance; while on the contrary, undervolting will cut back on heat and save you battery without hampering your performance.

There is no real danger to undervolting. The only side effect that you may encounter is a BSOD (Blue Screen of Death); this will occur if your voltages are set too low. However, if you properly test the stability of your set voltages you should not run into this issue. If you do in fact run into a BSOD, just restart your computer and reset your voltages to the last stable voltages.

To clarify the benefits and risks of undervolting, we complied this table:

Benefits	Risks
A cooler running notebook	BSOD
Enhanced battery time
Reduced fan noise
Extended notebook life .

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How to Undervolt Your Windows notebook

First you will need to download the following software. (click the title to start download)

RightMark CPU Clock Utility (RMClock) v.2.35

64bit users must download and extract the following file in the installation directory : Download

RMClock is a real-time utility that will be used to adjust your CPU’s voltages.

Orthos CPU Loader

Orthos stresses your processor and will be used to test for stability throughout the undervolting process.

HWMonitor 32bit | 64bit

HWMonitor is used to monitor the temperatures of your notebook.

Step 1

In order to find out how effective undervolting will be, it is important where you start.

1) Open HW monitor and let it run in the background.

2) Run ORTHOS and press “Start”, Let your notebook sit for 10 minutes and watch your temperatures.

3) After 10 minutes look at the maximum temperature for your CPU. If your CPU has more than one core, it will display the maximum temperature for each core. Take note of the maximum by either jotting it down or by taking a screenshot.

As you can see in the image below our processor hit 79C

(Click image to enlarge)

Step 2

In this step we will go through the proper method for setting up RMClock. It is important that users with Vista 64 bit operating systems use signed drivers, otherwise RMClock will not work.

1) Install RMclock by double clicking on the .exe file that was downloaded.

2) Run RMClock.

3) Once RMClock is open, click the “Advanced CPU settings” button on the left side. The latest version of RMClock should automatically detect your CPU. If it does not, then under “CPU type selection” at the bottom, select “Mobile” and check “Apply these settings at startup”.

*AMD Users must tick P-StateTransistors for a better undervolt

(Click image to enlarge)

RMClock may ask to restart the software, if it does, let it restart. After it has restarted, make sure RMClock is recognizing your CPU correctly by going to the “CPU info” tab.

Step 3

Now it is time to set up a Profile.

1) Double click the profile tab and click “Performance on demand”

2) Check “Use P-state transitions (PST)” for both AC Power and Battery.

Furthermore, check all the index boxes (scroll down to make sure you check all of them)

Click “Apply” when complete.

(Click image to enlarge)

3) Return to the main “Profiles” page

4) Change the current profile in the drop down menu to “Performance on demand”. Make certain you do this for both AC power and Battery.

5) Check all the index boxes; though if you have SuperLFM or IDA, leave them out for the time being.

6) Near the bottom, uncheck “Auto-adjust intermediate states VID’s”. Continue by pressing the “Default” button and click “Apply”.

(Click image to enlarge)

Step 4-1

Now that the profile is set up, it is time to get to the actual undervolting. On the main page, you will see different multipliers and voltages.

What is a multiplier?

Multipliers are incorporated with Intel SpeedStep Technology. 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.

As your notebook requires more processing power, the higher the multiplier your CPU will use. The higher the multiplier, the higher the corresponding clock speed will be. The higher the clock speed, the more voltage it requires to run and vice versa.

1) Start by lowering the highest multiplier’s voltage, in this case it is the 11x multiplier. The majority of users should be able to drop their highest multiplier by at least 0.100v. Start there and continue by slowly decreasing it.

2) Click “Apply” each time so the new voltage can take effect. This must be done each time the voltage is lowered.

Step 4-2

Each time the voltage is dropped, it is important to do a stability test. If your undervolt is unstable you will run into a BSOD.

1) Re-open ORTHOS and HWMonitor.

2) In RMClock, open up the “CPU info” tab. You can monitor the temperatures and statistics.

3) In ORTHOS, set the test type to “Small FFTs – stress cpu” to limit the test to the CPU. Run the test for a minimum of 45 minutes. I

f it does not crash after the test is complete, you can drop the voltage lower.  We suggest you go down by 0.025 v at a time until a BSOD or error warning occurs.

If you do get a BSOD or error, you have reached your limit and the voltage has been set too low.  If you have a BSOD, your notebook should restart and voltages should have reverted to the last stable voltages. Keep a record of good/bad voltages on paper. If there was an error in ORTHOS then raise your voltage.

There is no need to panic since it is normal to get a BSOD or error at some point.

Once you have found the unstable voltage, raise it up by two steps to put a safe margin away from the unstable voltage.

(Click image to enlarge)

Step 5

So far we have only dealt with the highest multiplier. If you wish to get the most out of undervolting, you can undervolt the other multipliers.

To do this follow steps 4-1 and 4-2 but when you do the stability tests, uncheck the multipliers above the one you are undervolting.

For those that don’t have the time or patience to undervolt the other multipliers, simply tick the “Auto-adjust intermediate states” box and it will fill in all the multipliers in between your Idle multiplier and the highest multiplier. It generally works well though there is no guarantee they are 100% stable as it calculates them mathematically.

In conclusion, we hope enjoy your cooler, quieter, and more power efficient notebook.