How to undervolt Lenovo Legion Pro 7 13900hx rtx 4090

[gamer86]

Hi everyone, i am newbie about undervolt. i read something about ThrottleStop but i dont know how to give value for undervolt to my laptop. i saw a video and gave same values but 2 times my laptop frozen on idle windows and than close undervolt from my bios and deleted trotterstop. Just i need to know which values is ok for my laptop. How can i give right values ? Thanks for ask and help.

Edit 1: I learned and i did undervolt with throtterstop program. I added my values. Please check on image. I have some when i check Limits. Idle time nothing happen but while i playing or test my computer( above 85 degree) start showing termals, PL1 and PL2 , EDP OTHER.

Edit 2: I added my game test images. Still too loud and hot my cpu even after did undervolt. How can i solve this ?

 

[unclewebb]

i need to know which values is ok for my laptop.

You have to experiment to find out what values will work best for your laptop.

Try setting mV Boost to 150. This might let you undervolt the CPU P Cache some more without your computer crashing. Try setting the P Cache offset to -75 mV or -100 mV after you set mV Boost to 150.

A laptop that has a 13900HX processor and a 4090 GPU is going to run very hot and the fans will make a lot of noise. Undervolting will only help a little bit. If you want a cooler laptop you have to reduce its performance. Is that what you want?

Open the TPL window and try setting the PL1 and PL2 power limits lower. Try setting them to 125W.
Less heat is good. Less performance is bad. You have to decide how much power and heat to run your CPU at.

You can also lower the Turbo Groups in the FIVR window to make your CPU run slower.
Maybe setting these all to 40 might be OK for playing most games.

 

[gamer86]

Check on this video. Same laptop but results are awesome. Also i did same things but It's so hot that I can't compare his laptop. If 13900hx has to be hot, why his the laptop cold? Can you explain to me ? I'm newbie and wonder this. Thanks for your answer.

 

[unclewebb]

Your screenshot shows that your CPU is going as high as 190.8W. That is why it is running so hot. Some 13900HX CPUs need more power and will run hotter. All CPUs are not exactly the same.

In the video the PL1 power limit is set to only 140W. This will reduce maximum performance but it will allow the CPU to run cooler during a long Cinebench test. Post a screenshot of the ThrottleStop TPL window. What are your turbo power limits set to? How hot is your room temperature? Are you using a cooling pad?

When he starts testing with Cinebench, his CPU is only running at 4.1 GHz. It is throttling. It is not even close to running at full speed.

At 140W in Cinebench, the CPU package is at 85°C. HWiNFO shows only 3.80 GHz. It is throttling more when the power limit decreases. HWiNFO does not report accurate MHz when a CPU starts to thermal or power limit throttle. It is obvious though that 140W is not enough power for maximum performance from a 13900HX.

why his the laptop cold?

When he is testing in the video and the Nvidia GPU is active, the CPU power consumption is only 71.8W but the CPU temperature is already up to 82°C. These laptop computers run hot. When his computer is running Cinebench at full power, his computer runs hot too. A 4090 GPU running at more than 170W puts a lot of extra heat into the laptop case.

Did you try adjusting mv Boost and lowering the P Cache offset? That has helped many users with these hot running CPUs.

 

[gamer86]

Your screenshot shows that your CPU is going as high as 190.8W. That is why it is running so hot. Some 13900HX CPUs need more power and will run hotter. All CPUs are not exactly the same.

View attachment 354947

In the video the PL1 power limit is set to only 140W. This will reduce maximum performance but it will allow the CPU to run cooler during a long Cinebench test. Post a screenshot of the ThrottleStop TPL window. What are your turbo power limits set to? How hot is your room temperature? Are you using a cooling pad?

When he starts testing with Cinebench, his CPU is only running at 4.1 GHz. It is throttling. It is not even close to running at full speed.

At 140W in Cinebench, the CPU package is at 85°C. HWiNFO shows only 3.80 GHz. It is throttling more when the power limit decreases. HWiNFO does not report accurate MHz when a CPU starts to thermal or power limit throttle. It is obvious though that 140W is not enough power for maximum performance from a 13900HX.


When he is testing in the video and the Nvidia GPU is active, the CPU power consumption is only 71.8W but the CPU temperature is already up to 82°C. These laptop computers run hot. When his computer is running Cinebench at full power, his computer runs hot too. A 4090 GPU running at more than 170W puts a lot of extra heat into the laptop case.

View attachment 354948

Did you try adjusting mv Boost and lowering the P Cache offset? That has helped many users with these hot running CPUs.

My room temperature is 24 degree and im not using cooling pad but i start checking cooling pad which one is quieter. I dont know how to set "turbo power limit". i can do if you tell me how to do. PL1 and PL2 i set 125 as you told me. should i set 140 ? No need maximum performance from the cpu. Cause cpu is already powerful for 2k ultra gaming. Also gpu same. What really matters is how can I make my processor run cooler?

By the way my laptop runs cool enough if i set balance mod on lenovo vantage but performance drops by 30-40 percent as i understand from fps while testing games. thats why i am trying to undervolt.

My another question: If I turn off cpu turbo, what percentage of performance loss will I experience?

 

[unclewebb]

If I turn off cpu turbo, what percentage of performance loss will I experience?

If you are curious, check the Disable Turbo box on the main screen of ThrottleStop. Go play a game and you can see for yourself how much performance you lose.

If your computer is still too hot when the turbo power limits are set to 125 then set them both lower to 100. Maybe 75 will be better for games. This is the best way to control your CPU. You will lose performance though so it is up to you to find a setting you like. You might need to adjust the power limits depending on which game you are playing.

I do not know what Lenovo Vantage Balanced mode does. It probably lowers the maximum CPU speed or it lowers the MMIO turbo power limits. That is all you can do if you want a cooler laptop. Lower the CPU speed or lower the turbo power limits.

Did you try adjusting mv Boost and lowering the P Cache offset?

 

[gamer86]

If your computer is still too hot when the turbo power limits are set to 125 then set them both lower to 100. Maybe 75 will be better for games. This is the best way to control your CPU. You will lose performance though so it is up to you to find a setting you like. You might need to adjust the power limits depending on which game you are playing.

What values should I change here? i am newbie, sorry for this. I just don't want to do anything wrong.

 

[unclewebb]

What values should I change here?

The Long Power PL1 and Short Power PL2 are already set to 125. It looks like you have already figured out how to adjust the turbo power limits.

To adjust the maximum CPU speed try checking the Speed Shift box in the TPL windows and lower the Speed Shift Max value. Try 30 to cap your CPU at a maximum of 3000 MHz. I do not use Windows 11 or own a 13900HX so you will need to experiment with this setting to see how it works. With a powerful Nvidia 4090, a slower CPU might still give you great game performance without creating as much heat.

 

[gamer86]

tried 30 - 35 - 40 -45 (Assassins Creed Valhalla ultra settings - 2k res - no fsr ) and never work cpu max 3000 Mhz. Still working 4800 Mhz instead of 5400 Mhz. Also tried disable turbo but still working on 80+ degree. Just i need to lock degree at 80. Cause after 80 degree fan start working noisy. My laptop working quiet below 80 degrees. Thanks for help and for your time.

 

[unclewebb]

In the Options window if you do not see a yellow lock icon hear the PROCHOT Offset setting, try setting PROCHOT Offset to 20. That will tell your computer to start slowing down when it reaches 80°C instead of slowing down at 100°C. Not sure if that will solve your problem but worth a try. Laptops with a 13900HX and a Nvidia 4090 were not designed to run cool when playing games.

 

[gamer86]

In the Options window if you do not see a yellow lock icon hear the PROCHOT Offset setting, try setting PROCHOT Offset to 20. That will tell your computer to start slowing down when it reaches 80°C instead of slowing down at 100°C.
Not sure if that will solve your problem but worth a try. Laptops with a 13900HX and a Nvidia 4090 were not designed to run cool when playing games.

Actually i need to open hidden setting on my bios but i couldnt. I did some research and tried some combinations but it didn't work. Maybe need to change AC/DC in Cpu setting if i find how to open hidden settings. I think this option will work. By the way PROCHOT offset setting work well. stuck max 80 degree and fans working less noisy. I need to ask 2 small question. i appreciate if you answer.

1) Is there any problem on my limits or everything ok ? I bought my laptop used one and invoice date is 1 year ago. that is, it has been used for 1 year. Should i renew thermal paste ?

 

[unclewebb]

Is there any problem on my limits or everything ok ?

Lowering the turbo power limits tells your CPU to power limit throttle. When you see PL1 or PL2 lighting up red under the CORE column of Limit Reasons, ThrottleStop is telling you that your CPU is power limit throttling. This confirms that your CPU is doing what you have told it to do, throttle.

Should i renew thermal paste ?

I do not know how long Lenovo thermal paste will last. My 4th Gen Lenovo laptop has used the same thermal paste for more than 10 years. It still works more or less the same.

You only need to replace the thermal paste if you have noticed a significant change over time. If everything is exactly the same with your MHz and power limits and room temperature as it was 6 months ago and now your games are running 10°C or 20°C hotter, that would be a good time to open your laptop and at least blow out the dust. If that does not make any difference, consider changing the thermal paste with some Honeywell PTM 7950.

I do not think your temperatures are any worse than any other similar laptop when it is allowed to go as high as 190W. Laptops with a 13900HX and a Nvidia 4090 GPU cannot provide maximum performance at only 80°C.

PROCHOT offset setting work well

That is good to know. Adjusting PROCHOT Offset is a good trick that not many people use.

 

[gamer86]

Lowering the turbo power limits tells your CPU to power limit throttle. When you see PL1 or PL2 lighting up red under the CORE column of Limit Reasons, ThrottleStop is telling you that your CPU is power limit throttling. This confirms that your CPU is doing what you have told it to do, throttle.


I do not know how long Lenovo thermal paste will last. My 4th Gen Lenovo laptop has used the same thermal paste for more than 10 years. It still works more or less the same.

You only need to replace the thermal paste if you have noticed a significant change over time. If everything is exactly the same with your MHz and power limits and room temperature as it was 6 months ago and now your games are running 10°C or 20°C hotter, that would be a good time to open your laptop and at least blow out the dust. If that does not make any difference, consider changing the thermal paste with some Honeywell PTM 7950.

I do not think your temperatures are any worse than any other similar laptop when it is allowed to go as high as 190W. Laptops with a 13900HX and a Nvidia 4090 GPU cannot provide maximum performance at only 80°C.


That is good to know. Adjusting PROCHOT Offset is a good trick that not many people use.

I will go to technical service or official lenovo service for replace thermal paste. i will buy Honeywell PTM 7950 as you told me. Surely you are right. After all, it's summer. It's normal for laptops to get a little warmer. I also lowered the processor wattage settings a bit from lenovo vantage app. Everything good for me especially after set PROCHOT offset
Thank you again for your help.

 

[tangelo]

I will go to technical service or official lenovo service for replace thermal paste. i will buy Honeywell PTM 7950 as you told me. Surely you are right. After all, it's summer. It's normal for laptops to get a little warmer. I also lowered the processor wattage settings a bit from lenovo vantage app. Everything good for me especially after set PROCHOT offset
Thank you again for your help.

AFAIK these laptops use liquid metal.

 

[Intrepidity]

I will go to technical service or official lenovo service for replace thermal paste. i will buy Honeywell PTM 7950 as you told me. Surely you are right. After all, it's summer. It's normal for laptops to get a little warmer. I also lowered the processor wattage settings a bit from lenovo vantage app. Everything good for me especially after set PROCHOT offset
Thank you again for your help.

Your laptop has liquid metal on CPU and PTM on GPU from factory, and you want to replicate that. Depends where in the world you are, but it seems Lenovo support tech don't have good guidelines regarding these laptops. A Lenovo tech might apply regular thermal paste to both making it a lot worse. You currently don't know if there is anything wrong or not. It's supposed to be hot and loud. You need a controlled test in order to obtain 1. benchmark results and 2. core delta. If all cores have identical load the temperature difference between them in degrees is the best indicator of how good the liquid metal application is. Seems like a question for a different forum.