The main thing that has changed with the new BIOS versions that are being pushed out is that Acer now enables the “Overclocking Lock” to prevent modifications to core voltage and turbo boost ratios from within windows regardless of privilege. This prevents any voltage modification using any Windows software such as Throttlestop.
To undo this change we need to first find out the specific location of the bit that enables and disables the OC lock, then use a tool to go in and modify the BIOS to disable the OC lock
Explanation and video at the bottom of the post.
Disable Secure Boot by going into BIOS > Boot > Secure Boot > Disabled.
You can re-enable secure boot once you unlock UV.
Download this tool and extract the contents inside the zip folder to
C:\insyde-tool after you do that, open a cmd.exe prompt as administrator then enter
Then enter command
dir to confirm you are in the right directory, you should see multiple files including “H2OUVE-W-CONSOLEx64.exe”. once you are there, run the following command
H2OUVE-W-CONSOLEx64.exe -gv vars.txt
Note: If you only see a folder named “InsydeH2OUVE_x86_WINx64_200.00.01.00” or similar, bring the contents of that folder outside into “insyde-tool” or use the
cd command to change the directory to that folder.
That command should create a file named “vars.txt” in the folder where you extracted the tool to earlier. Open with notepad to edit. CTRL+F to search for
CpuSetup. Find the value as shown in the screenshot. Additionally take note of the value underlined in red. (It varies on each vars extraction)
Change the value from 01 to 00.
Row containing 000000D0. Last column.
After changing the value that is highlighted in the picture, save the file as
vars-m.txt in the same directory and you can close it after it is saved
Go back to the same command prompt and run this last command
H2OUVE-W-CONSOLEx64.exe -sv vars-m.txt
and you are done, reboot and you should have undervolt working.
To verify the modification is successful, check for the following entry based on the red underlined value taken earlier. Since mine is [05B], I should be looking for
Variable Index[05b]: Set Successfully
Ignore other lines.
Original Guide Written by u/dglt1
Edited for convenience
Video Tutorial – https://youtu.be/lYSKzZRQcOA (The value changed here is different. It has 0xDA while 11th gen Helios has 0xDF. Check highlighted image above.)
Basic Throttlestop and Undervolting Guide (After you unlock UV) – https://youtu.be/QCDIK-nnois
What did you just do?
Read here for an extensive guide.
- It involves changing a bit that enables “Overclocking Lock” which prevents voltage and turbo ratio modifications through windows
- The location of the bit for Helios 300 2021 (11th gen) BIOS is 0xDF
- The guide may work for your non Helios laptop if it has insyde bios and you are able to correctly locate the bit required to edit
- Rather than relying on RUefi or other UFI shells to modify the vars, we used a method as shared by dglt for the Legion 5
Acer Gaming Discord Server – https://discord.gg/UF9eARcQQn
Legion Discord (Source of the guide) – https://discord.gg/legionseries