[GUIDE] How to undervolt laptop (Intel CPU and Nvidia GPU, 2021 revised version)

This is my own guide on how to undervolt Intel CPU / Nvidia GPU in your laptops. Hope you found it useful!

Notes:

• This is my own method on how to do it. There are a lot of ways to undervolt CPU+GPU, but this is how I usually undervolt with all the laptops I had reviewed and with my own laptop
• I will try my best to make the explanation clear and will be using the undervolt profiles in my laptop as example
• As mentioned in the title, this guide is for those with Intel CPU (4th gen or later) or Nvidia GPU (10 series or later) or both only. Some laptops have BIOS version with Plundervolt patch that locks CPU voltage control, so take note
• You might brick your 10th/11th gen Intel laptop if you undervolted too much even with software like Throttlestop, I will not be responsible if something catastrophic happens
• To TGL-45 laptop owners: Only i7 and i9 has unlocked CPU voltage control, even so the laptop model itself might not allow you to undervolt the CPU. Check your laptop model first before proceeding

CPU undervolting:
I prefer using Throttlestop instead of Intel XTU since I had bad experiences with XTU and TS provides more options on CPU tuning. First, download TS from here:
ThrottleStop (9.4.2 Beta) Download | TechPowerUp

Extract the folder, then launch Throttlestop Application. If you see an error, download this:
Download Visual C++ Redistributable Packages for Visual Studio 2013 from Official Microsoft Download Center (click download, tick x64 and x86, click next and install both of them after finishing downloading)

Initializing Throttlestop:
After opening Throttlestop, click turn on

Go to options, tick 'start minimized' and 'minimize on close'. If you want, you can also tick 'Nvidia GPU' and 'battery monitoring'

Click save

Now the main part - Undervolting:

Go to FIVR, click on 'CPU cache', tick 'unlock adjustable voltage'

Under adaptive (default setting) - offset voltage, slide left to -50mV (-49.8mV). This is the undervolt we would start from, though you can start from -100mV if you're confident that it will not crash.

Note to 10th/11th gen users: Start from -50mv and slowly increase the undervolt. Usually for 11th gen you can stop at -75mV, -100mV is the max and do it at your own risk.

IMPORTANT: Click on 'OK - do not save voltages', then click apply and OK

Apply the same undervolt for CPU core by repeating the steps above for CPU cache. You can undervolt CPU core first then CPU cache, it doesn't matter. Usually CPU core can be undervolted slightly more, but you can leave it as the same with CPU cache since there isn't much difference anyway.

Now the tricky part: Testing stability:
There isn't a good way to test it. Usually I would suggesting running Cinebench multi core rendering for the first test. If it doesn't crash during and after the rendering, increase the undervolt value by -5mV/-10mV increment (eg from -50mV to -55mV/-60mV) and repeat the rendering test. If it crashes, usually what would I do is to reduce the undervolt by 15mV/20mV (eg -150mV to -135mV/-130mV). After that, use it for a few days - browsing web, watching YT videos etc. Playing games is also a good way to test stability. Remember to open Throttlestop every time you turn on your laptop since we haven't setup task scheduler.

If it doesn't crash/freeze for a few days, go back to FIVR and click 'OK-save voltages immediately', click apply and OK.

To auto run Throttlestop after startup, follow these steps:
First, search task scheduler and run it. Under task scheduler library, click 'create basic task'

Type a name, click next

Select 'when I log on', click next

Select 'start a program', click next

Browse and select where Throttlestop.exe is located, click next

Tick the following, click finish

Under general tab, tick the following

Go to 'conditions' tab, untick all including the greyed ones

Under 'settings' tab, untick all except 'allow task to be run on demand'. Click OK. Done!

Additional CPU tuning:
1. Untick BD PROCHOT – from what I know, sometimes when CPU or GPU is thermal throttling, the other (GPU or CPU) will auto downclock to provide more thermal headroom

2. Unlock power limits (will work in most cases) – modify power limits/duration, sometimes it won’t work due to BIOS/firmware overwrite. Will expand this section soon with more explanation

3. Speedshift – set to a smaller value if you encounter clock speed drops in games not due to power/thermal throttling and wanted max clock speed. Works like high performance mode in Windows. Note that sometimes clock speed will not be at max in some games since it doesn’t need the extra performance (to save power), therefore increase in clock speed will not have higher FPS. Set to a bigger value if you don't want the clock speed to boost too much

You can also do a custom profile, let's say you want a low power profile for light loads/battery or slightly lower all core clock speed for games. There are 4 profiles that can be saved. To rename the profile name just go to options and rename here:

GPU undervolting:
I prefer using MSI Afterburner to undervolt GPU, you can download it here: Afterburner (msi.com).

Download Unigine Heaven - needed for testing: UNIGINE Benchmarks

Download HWinfo64 - Download HWiNFO latest release (fosshub.com)

If cannot run Unigine, download this first:

Download Microsoft Visual C++ 2010 Service Pack 1 Redistributable Package MFC Security Update from Official Microsoft Download Center

In this case, I will be using my laptop as an example which has a RTX 3060 GPU. Before we proceed, we need to setup HWinfo64 for monitoring purposes.

Open HWinfo64, tick 'sensors only' and click run.

Go to settings.

Under 'General' tab: Change polling period - global to 500ms, disk SMART to 120 cycles. Then click set. Click OK.

Scroll down until you see GPU monitoring:

First thing you need to do is to run Heaven. Under 'preset', set to Extreme, then change back to Custom. Change resolution to 1920x1080, untick fullscreen. Click run.

When the scene has started, go to HWinfo64 and click on the clock button immediately.

Let it run for 5 mins (the longer the better actually) and record the average clock speed taken from HWinfo64. Make sure it's running with dGPU not iGPU. In this case I got around 1918MHz for RTX 3060.

Let Unigine Heaven continue to run. Open MSI Afterburner. First thing to do is to enable auto startup by clicking the Windows icon (red means on). Then, open voltage frequency curve in Afterburner.

Put Afterburner and voltage frequency curve left/right or top/bottom.

Slide core clock bar to right to +120 (+120MHz). Click apply.

Back to the curve, find the voltage that has the closest clock speed you have recorded just now, by clicking those dots in the curve. Since I got 1918MHz, I click at the dot with 1912MHz, which is at 0.906V. Then, hold Shift, and drag from the area just after 0.906V to the end of the curve. You will see a slight highlighted area.

Select the last dot in the curve (at 1250mV), drag it down to 1912MHz.

Click apply. You should see a straight line after 0.906V. If not, use the Shift and drag method to make the dots above 1912MHz back down to 1912MHz.

Save it to a profile: Click the diskette button and click on any number.

Of course, you can try higher values like +135 (+15 intervals in 16/20 series, +7/8 intervals in 30 series). Remember to test the GPU stability with games.

IMPORTANT: The curve might change slightly when the GPU is idling or under load. While idling, the dots in the curve with higher voltages might be above the clock speed you set. Use the Shift and drag method to make the dots above 1912MHz (using my example) back down to 1912MHz. While under load, the final clock speed might be slightly above or below the clock speed you have set. In this case, make adjustments on the core clock bar: Let's say if it drops to 1905MHz from 1912MHz, you can set higher OC like +128 to counteract it.

Now the tricky part: Testing stability. For the first test, run Heaven. If the GPU is stable after 1 run, use games to test stability instead. This might take several days.

• If it's not stable, try using slightly lower clock speed (eg +112 instead of +120) or use slightly higher voltage for the clock speed you have set.
• If it's stable, you can try to undervolt more by either increasing the clocks speed slightly (eg +128 instead of +120) or use slightly lower voltage at the same clock speed.

If you still have doubts, feel free to comment below. Happy undervolting!