# i7-9750H - Can't undervolt after upgrading to Windows 11 (even after rolling back to Windows 10)



## amrnada (Nov 18, 2021)

Laptop: Asus Hero 3
CPU: i7-9750H - BIOS v308 (used to allow undervolting)

So everything was find with Windows 10, and then I decided to upgrade to Windows 11 (finally was ready for my device)
After upgrading directly, I noticed that my laptop updated the bios, same happened on Windows 10 but I rolled back from v309 to v308 and stopped the auto BIOS update and all was good
So I did the same thing and rolled back to the old BIOS v308, but surprisingly it's no more undervolting!! After some research on Google, I found that it's a common issue with Windows 11, so I tried all the solutions that I could:

1. Disabling Virtualization (from BIOS as well along with another option which I forgot)
2. Disabling Hyper-V
3. Disabling Virtual Machine Platform
4. Disabling WSL2
5. Disabling Core Isolation (not available in settings after disabling some other stuff)
6. Deleted the INI file - even downloaded the latest beta version v9.4.2 Beta

I even rolled back to Windows 10, but to my surprise, undervolting was not working anymore! So I updated again to Windows 11

After ALL this, still undervolting is greyed out  Can anyone suggest any other solution that I can try?


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## unclewebb (Nov 18, 2021)

amrnada said:


> I even rolled back to Windows 10


Did you try reinstalling the older BIOS version after rolling back to Windows 10? You might be forced to wipe the hard drive and do a clean install of Windows 10.

Your BIOS has locked out CPU voltage control. There is nothing ThrottleStop can do to fix this problem. Your screenshot shows that ThrottleStop has access to the CPU voltage control register. It just cannot do anything with that register because the BIOS has locked it. The Windows features are not causing any problems. It is the BIOS.

Try searching a notebook specific forum like Notebook Review. Someone with your laptop model must have encountered the same issue. Maybe there is a solution.


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## amrnada (Nov 18, 2021)

unclewebb said:


> Did you try reinstalling the older BIOS version after rolling back to Windows 10? You might be forced to wipe the hard drive and do a clean install of Windows 10.
> 
> Your BIOS has locked out CPU voltage control. There is nothing ThrottleStop can do to fix this problem. Your screenshot shows that ThrottleStop has access to the CPU voltage control register. It just cannot do anything with that register because the BIOS has locked it. The Windows features are not causing any problems. It is the BIOS.
> 
> Try searching a notebook specific forum like Notebook Review. Someone with your laptop model must have encountered the same issue. Maybe there is a solution.


Thanks for your reply.

Actually yes, I did reflash the old BIOS on Windows 10, but not luck

Is there anyway I can reset the BIOS without deleting the whole windows? that's much work to do :/

I also went directly to the forum that u recommended, but so far, no once is talking about the undervolt issue...

*UPDATE: *THANKS GOD I found a very old version of BIOS (online) that came with the laptop v307 in 2019, which is not listed on Asus website lol! Was very worried that it would kill my laptop since I downloaded it from a 3rd-party website "driverscollection.com", but thanks God it worked and I was able FINALLY to undervolt again, even though undervolting was working with v308, but for some reason, it got cursed after upgrading to Windows 11.


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## unclewebb (Nov 19, 2021)

Good work. 

For your undervolt settings, the core and the cache offset voltages do not have to be set equally. Most 9750H perform best when the core is offset -50 mV to -100 mV more than the cache. Use Cinebench for testing purposes. 

Your Intel GPU undervolt will be ignored unless you also undervolt the iGPU Unslice equally. I would set both to 0.0000. Get the core figured out first.


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## Bacondoggie (Apr 14, 2022)

amrnada said:


> Thanks for your reply.
> 
> Actually yes, I did reflash the old BIOS on Windows 10, but not luck
> 
> ...


Hi, I did the same thing and turned off the settings you listed, and installed v307. I have the same laptop as well but it isnt working. Any tips?


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## Eegii0558 (Apr 15, 2022)

unclewebb said:


> Most 9750H perform best when the core is offset -50 mV to -100 mV more than the cache.


what about 8750H ?


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## unclewebb (Apr 15, 2022)

Eegii0558 said:


> what about 8750H ?


The 8750H and 9750H react the same to different voltages.

Requesting a bigger core offset compared to the cache offset seems to improve performance or temperatures when running software that uses a lot of AVX instructions. The best way to test for this is to use a consistent program like Cinebench R20 or R23.

I have never owned or had access to either of these CPUs so I have never had the chance to do some testing to prove this one way or the other. Most 8750H are stable with the cache at -125 mV and the core offset at -175 mV to -225 mV.


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