XPS 17 9720, cannot undervolt after BIOS update to 1.12.0 and 1.13.1

This issue occurs on another Dell XPS 17 9720 after updating to 1.13.1. Throttle Stop shows that the device is unlocked, but the voltage offsets are not applied.

The latest Intel XTU version shows a message that the undervolt protection is turned on. It means memory areas controlling voltage offsets are locked.

I decided to check it because the new version of BIOS might use new addresses (offsets) for those settings and found that they weren't changed in the latest BIOS version (1.13.1): 0x43 for CFG Lock and 0x10E for Overclocking Lock. The store is also the same: 0x3 or CpuSetup.

It looks like there is a problem with the particular BIOS release.

Same issue for me with my 9520. It happened with BIOS 1.8 and remained in 1.9. Even the registers are the same for the XPS 15.

All advantages of the 12900HK are gone with theses updates as they seem to have changed the embedded controller (ECC) with update 1.8 on the XPS15.

I'm unsure if it is related to the EC firmware (it was also updated from 1.0.3 to 1.0.4), but the new BIOS version definitely disabled the undervolting.

I hope it is a software bug and not the new Dell policy to remove features customers paid for.

XPS 15 and XPS 17 are expensive devices, especially in the top configurations. I don't mind paying a premium for a better machine and service, but now my experience is rather negative.

I had an issue with a key on the keyboard. So it was replaced with the new palm-rest assembly. And it also had a problem with another key, rough edges, and 0.5mm shifted to the bottom case (D).

On top of that, there were issues with buggy drivers and power limits. PL1 was locked to 20W. It was solved by the motherboard replacement and reinstalling Windows.

Now I have a problem with undervolting and the new BIOS... Great!

That's different from what I expect from a $3800 device. I hope that Dell will fix this issue.

I have the same problem on XPS 9720 with Core i9 after updating BIOS to 1.12.0. The undervolting is unlocked, but it is not applied.

I'm very confused about this problem, it looks like some kind of fraud, when you pay premium for the unlocked CPU and then Dell decides to disable this feature.

I really like my XPS 17 and don't want to return it because of that.

Just wanted to add in that im having the same issue with 1.8.1/1.9.1 BIOS on the XPS 9520.  Without undervolting, my laptop fans are constantly on and have drastically reduced battery life.  Please fix this Dell.

Yes, the main reason I decided to go with the more expensive Core i9 option is the undervolting support. It allows me to reduce the noise level during light loads, achieve a better battery life, and get some real performance boost. The noise level is a few dBA lower, and the fans kick in less frequently.

The BIOS downgrade is a workaround, not a solution. I want to get the BIOS updates and premium support I've paid for.

hi, I am interested in this. not sure how you notice this...can you please share some pictures? 

Dell has been doing this since years now. Every time a new XPS releases after a couple of bios updates they cripple your cpu so it throttles and we cant undervolt. This way they promote their newer machines.

Undervolting is a pretty exciting feature allowing you to decrease the CPU voltages. It makes the laptop consume less power while offering the same performance or getting better performance on the same power limit.

For example, if you decrease the voltage of Core i9 12900HK CPU by 0.15V, it will consume ~20-40% less power depending on base voltage (it depends on the CPU load).

As a result, the laptop will generate significantly less noise on light tasks and get 10-15% more performance under full load and 45-55W PL1.

Unfortunately, a few years ago, Dell decided to disable undervolting by default in the hidden BIOS settings, but it is possible to bypass that and enable it. There are two hidden options controlling that: CFG Lock and Overclocking Lock.

Once those locks are disabled, you can undervolt your laptop and get all the benefits.

In the recent 12th and 13th gen mobile CPUs, the undervolting is available only on HK and HX series. So you need to pay $300-$400 more to get this feature. There's no other reason to go with 12900HK instead 12700H.

But in the recent versions of BIOS for XPS 15 and 17, Dell decided to disable this feature altogether. So those hidden options are still there, but they are ignored, and the undervolting is not applied.

It is a main problem. I still hope this is a bug.

Previously, I used Dell Inspiron 3779 for more than four years and hadn't had this issue. In the beginning, the undervolting was fully unlocked, then in 2020, Dell locked it on the BIOS level (with those two hidden settings), and now it continues working.

As for other devices, at this point, I don't think my next laptop will be from Dell. I can close my eyes on many issues even in such an expensive laptop (build quality issues, problems with drivers like Intel DTT, issues with the sleep mode, etc.), but the locking features I've paid for that's too much.

Other vendors like Asus or Lenovo have those settings in BIOS. I don't need to spend my time finding the right NVRAM offset.

Today I upgraded the BIOS to 1.14 to check if the issue with undervolting was fixed. The problem is still there. In addition, I got a severe performance degradation compared to the previous version.

Now the performance is 17% lower. I described this problem in a separate thread.

More important, there's no option to downgrade the BIOS version.

Read this:

https://www.reddit.com/r/intel/comments/10dcjd9/intel_blocks_undervolting_on_alder_and_raptor_lake/

Sorry to tell you this, but undervolt is gone.

It's a much more complicated story. Technically, it is still possible to undervolt the CPU using hidden settings in BIOS, but this feature is broken on XPS 15 and 17 due to bugs. Also, the undervolt protection can't be disabled, at least with the current version of BIOS.

Unfortunately, the problem is still there. It's related to any voltage offset adjustments. The laptop's CPU enters some failsafe mode with 400 MHz clocks, which is incorrect behavior.

I don't have any machine that's in this topic but if someone would mind checking to see if putting the PC to sleep and waking it has any effect. On my dells I can unlock the registers allowing voltage/overclocking adjustment after a sleep wake cycle. Currently working on some bios modifications to do better than that.