I don't have a solution but I have the same problem! What I've discovered is the CPU will force all tasks into a single thread and change the active thread every 10-15 seconds. I've also done everything under the sun to try and narrow down this problem.

I've done everything you mentioned plus:

• Modified CPU settings in BIOS to force behavior change.
• Disconnected all peripherals.

Are you using Windows 10 or 11? I've got 11 and I've considered setting it up with 10 instead to see if that makes a difference.

Are your laptops also running a Core i5-1240P?

Thank you for your reply @carrellslake 

We are using Windows 10 and were considering setting it up with Windows 11 - that saved us some efforts.

We also did some CPU stress tests and found that under prolonged CPU load the performance gradually degrades until at some point enters what I think is "low performance mode". This is good for short term heat reduction, but the problem is the CPU doesn't exit that mode unless you restart.

We are also considering testing with disabled "Intel Speed Step Technology" option in the BIOS, but that will be tomorrow.

Edit : CPU is Core i5-1240P too

I tried multiple BIOS setting changes related to CPU performance and nothing helped. I can confirm, at least for my laptops, that CPU temps are not the problem either.

I suspect the fix for this may be related to the processor itself. Intel might have to be the one to provide a solution.

One more thing I forgot to mention - we tried also to edit the Windows power plan and reduce the "Maximum processor state" to 70% . So far the laptop is working a bit more stable, but this is more of a temporary workaround than a solution.

This is good for short term heat reduction

Rolling back to May BIOS 1.2.2 seems to improve the situation.

The only issue now is disabling Windows update BIOS enforcement until a more stable version is released.

@carrellslake  please test and share results if you can

Thanks for the suggestion, I'm trying it now. Since it happens somewhat randomly, it could be days before I think this is the fix.

I am also currently also experiencing the same issues with CPU usage, the issue is intermittent. It seems that when the Windows Update installs the Windows Drivers from Intel (INTEL - System - 10.1.45.4 &INTEL - System - 10.1.36.6) the system becomes very unstable. 

This is a very temporary solution and not a very effective one as I had to disable driver updates.

Also, all updates for drivers were done using DELL Support Assistant. 

Has anyone found a more permanent solution for this issue?

FYI Dell Command Update application can also push the BIOS update.