# Please help me to undervolt XPS 7590



## Roy2001 (Feb 11, 2021)

I bought 2 Dell XPS 7590, with exactly same spec. They are with i7-9750H CPU, to be more specific, both are with 16GB/512GB, OLED and 1650 dGPU.

I got 1st one in January. It came with BIOS 1.8.1. I reverted it back to 1.5.0 and ThrottleStop works like a charm and it is very quiet.

It works so good that I recommended it to a friend. The laptop arrived with BIOS 1.8.1. This time, I did clean Windows 10 installation, then reverted BIOS back to 1.5.0, but it shows FIVR control locked and turbo clock locked. I tried BIOS 1.2.3 then back to 1.5.0, still ThrottleStop does not work.

Please let me know your thoughts. I wonder if the new windows installation causes the problem which I really don't think so. But I could not figured out why. I downloaded both 9.2 and 9.2.9 beta version still no use. Now this new laptop is noticeable warmer and nosier than the other one.


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## unclewebb (Feb 11, 2021)

Roy2001 said:


> Dell XPS 7590


Your BIOS or a Windows update has locked CPU voltage control. Did you try using the BIOS option, Reset to Factory?

If that does not work, you can edit a couple of UEFI variables to unlock CPU voltage control.


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		https://www.reddit.com/r/Dell/comments/fzv599


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## Roy2001 (Feb 13, 2021)

unclewebb said:


> Your BIOS or a Windows update has locked CPU voltage control. Did you try using the BIOS option, Reset to Factory?
> 
> If that does not work, you can edit a couple of UEFI variables to unlock CPU voltage control.
> 
> ...


I converted a 32GB USB drive from MBR to GPI, and formatted it to FAT32, I verifyed this in disk management. But refuses to boot with downloaded EFI/BOOT/bootx64.efi. The USB is empty with only that directory and file. Did I miss anything? Here is the message. Thank you!

*Operating System Loader failed signature verification. WARNING: The file may have been tampered with! All bootable devices failed Secure Boot verification.*


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## unclewebb (Feb 13, 2021)

@Roy2001 - The error message says that you need to disable Secure Boot. Did you do that step?


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## Roy2001 (Feb 13, 2021)

unclewebb said:


> @Roy2001 - The error message says that you need to disable Secure Boot. Did you do that step?


I disabled it and now I can undervolt again. Thanks a lot for help! Sorry for my ignorance. Appreciate it!


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