Undervolt XPS 15 (or other intel CPU's) when undervolting is locked;

[Gianniis_]

Heya, a laptop gamer here
(XPS 15 9560) Intel i7-7700HQ kaby lake

Recently i've had more problems with throttling and higher temps, so naturally i started to wonder why.
After some thorough investigation i found out that Intel had a thing called "plundervolt" which means with an undervolted CPU there were more errors and possible data leaks.

This broke my fps massively, as someone who modded the shit out of my trusty old XPS 9560, without undervolting it wouldn't have mattered.
So here is my fix after +/- 6 hours of researching.

Step 1; delete XTU and Throttlestop.
Step 2; download any BIOS update before may 2020(!) (links below)
Step 3; install said BIOS version but when its starting up GO TO BOOT SETTINGS (spam F8/F12 keys)
step 4; when in boot settings make sure you click "reset bios settings" then RESET SETTINGS TO DEFAULT
Step 5; after your device has restarted restart your device to again go to the BIOS settings for the second time
Step 6; under the tab security TURN OFF "UEFI Firmware update via capsules"
Step 7; Make sure to safe your settings then your pc starts normally again.
Step 8; Install an older version (link below) of XTU do what it says and restart
Step 9; after the restart undervolt your CPU to whatever you feel like doing.

you can check with throttlestop if the undervolt has worked in their "FIVR" screen, but personally i wouldn't undervolt there because it'll sometimes lock, even though your CPU voltage isn't.

Hope to have helped anyone who wanted to do this
Gianni

Links
(if any of these dont work, search any version of the software before may 2020)

Xps 15 9560 BIOS pre Plundervolt: https://www.dell.com/support/home/n...9&oscode=wt64a&productcode=xps-15-9560-laptop
Older version of XTU: https://www.techspot.com/drivers/driver/file/information/16919/
Throttlestop: https://www.filehorse.com/download-throttlestop/old-versions/

 

[Caring1]

And all of that has been posted previously in Throttlestop help threads, thanks for taking the time to read them.

 

[22duckys]

I am trying to do this as my XPS 15 is basically a brick at this point. However, I can’t downgrade the BIOS by any of the methods anyone has described. I’ve done all the proper boot menu setting switches at the right time, I’ve even tried using the bios flash recovery. But without fail, my attempts to get to 1.18.0 from 1.19.2 never work. The computer always boots up in 1.19.2 even after an bios exe has run completely, even when factory settings are reapplied and then I disable capsule firmware updates.

I’m at my wits end with this because my laptop is basically a brick and every forum is filled with solutions that I can’t use because I can’t get past step one that everyone assumes will work and breezes past. Any suggestions?