Something keeps changing Processor Max Frequency in Windows Power Plan, is that Intel drivers?

[PTwr]

Hello,

I got a laptop with Ultra 9 285H and I observed weird behavior of which I am unsure if its Windows, Intel drivers, or OEM bloatware. I do not observe that on my other Intel-powered devices, but none of them is from new Ultra series.

Something constantly writes to registry keys holding "Maximum Processor Frequency" (level 0, which is "performance" cores), which prevents me from setting up an "ultra low wattage" power plan.

As its executed by svchost, its annoying to pinpoint. Process has only Microsoft binaries loaded, and from stacktrace it looks like some RPC done through service for elevated privileges (those registry keys have annoying ACL where normal Admin can't edit them).

Given that the behavior is idiotic, and even includes Buffer Overflow's, I'd place my bets on OEM bloatware. But it does not hurt to ask just in case.

Is that something done by Intel drivers?

[PTwr]

Here's better screenshot:

Some garbage first checks Power Settings, to figure out which registry keys hold Processor Max Frequency. Then it changes the settings for Windows default "Balanced" (381b4222....) and for my custom plan (a1dc4b4c...).

54533251-82be-4824-96c1-47b60b740d00 is Procesor directory, 75b0ae3f-bce0-45a7-8c89-c9611c25e100 is Performance Core Max Frequency, Efficiency Cores ends with 101. (Low power, ending with 102, are not changed)

[DeancR_Intel · Accepted solution]

Hi PTwr,

Thank you for contacting Intel support regarding the unusual registry behavior you're observing with your Intel Core Ultra 9 285H processor. I appreciate the detailed screenshots and technical analysis you've provided - this level of documentation is very helpful for understanding the issue.

Your observation about constant writes to the "Maximum Processor Frequency" registry keys for performance cores (level 0) is indeed concerning, especially since it's preventing you from setting up an ultra-low wattage power plan. The fact that this behavior includes what appears to be buffer overflows makes it even more problematic.

Based on your analysis showing:

• Registry modifications to both Windows default "Balanced" power plan and your custom plan
• Specific targeting of Performance Core Max Frequency settings (75b0ae3f-bce0-45a7-8c89-c9611c25e100)
• Execution through svchost with elevated privileges via RPC calls
• Behavior not observed on your other Intel-powered devices (non-Ultra series)

This could potentially be related to:

1. Intel's new power management features specific to the Ultra 9 285H processor
2. OEM-specific power management software
3. Windows power management interactions with the new Ultra series architecture

Just to be thorough in our investigation, I also recommend contacting your laptop's OEM (manufacturer) regarding this issue. Since you mentioned this behavior is not observed on your other Intel devices and given the nature of the registry modifications, there's a possibility this could be related to OEM-specific power management software or system optimization utilities that may have been pre-installed on your laptop. OEMs sometimes implement their own power management solutions that can interact with or override standard Intel power management features. They would have the most comprehensive knowledge of any proprietary software or drivers specific to your laptop model that might be causing this behavior.

Best regards, 

Dean R. 

Intel Customer Support Technician 

[DeancR_Intel]

Hi PTwr,

I wanted to follow up on the previous message regarding your inquiry. Have you had a chance to review it? If you have any questions or need further information, please let me know. 

Best regards, 

Dean R. 

Intel Customer Support Technician 

[PTwr]

Thank you for interest and sorry for late reply, I was off the grid for few days and managed to calm down after my initial infuriating discovery.

Long story short, I set Windows to "Best Performance" and got longer battery life

I had some time to look deeper into the "issue", and now I am fairly sure the culprit is a mix of Microsoft (by providing black-box tools and hiding settings from users) and OEM (by making "gamery" power plans on office machines) crafting up some nefarious "provisioning" which then is automatically forced into Windows install. Aside from clumsy "auto-tuning", there's some provisioned garbage doing some changes to power plan when switching between battery and wired (and also the "slow charger" event triggers).

Turns out the Registry write spam occurs only on "Balanced" overlay (the thing set in new Settings screen, not the actual power plan), and the "solution" was to set it to "Best Performance". And that behavior, I think, I have noticed on my other device(s) while I was discovering that there is virtually no difference between three overlays on machine with no dedicated GPU.

The device in question is Asus Zenbook Duo, which has some unique thermal challenges duo to OLED screen being rather poor choice for a heatsink.

The end effect on Balanced overlay was max frequency setting jumping up and down around 4Ghz (and some more complex settings changing as well) to chase some arbitrary thermal goal, fan was annoyingly "breathing" due to unstable temperature, and "idle" CPU consumption dominated by power plan constantly adjusting itself...

On Performance overlay there is no constant tinkering with CPU by Microsoft/OEM, and once chip is free to self-tune everything works better and at lower wattage.

I have not expected to venture on a road of becoming an expert in Windows power management when buying a new laptop, but at least I got something interesting to tinker with on rainy afternoons.