i9-14900HX laptop suddenly stops allowing turbo mode

[hpetrus]

I'm the owner of a Eurocom RX416 laptop, sporting an Intel i9-14900HX CPU, running Arch Linux.  Until recently, I was able to run it in both intel_pstate=active or intel_pstate=passive with turbo boost turned on without real issue.

Suddenly, without the fault of kernel updates or microcode changes, no_turbo is set to 1 and nothing I do - even with root permissions - will allow me to change the no_turbo state to 0.  The error is always the same:  'Operation not permitted'.

After exhaustively running after the situation on the OS/BIOS/kernel side, I'm fairly convinced this is a hardware issue.  It came out of nowhere on my system that was built for stability on-set for animation and VFX movies.

So, I'd like to ask this community for whatever help might be available in ascertaining what might be the problem.  I'm extremely well-versed in all things hardware and software, so I'm not squeamish enough not to dive into whatever I have to.

If there's someone from Intel looking at this, please chime in.  I really need help.  Whatever info you need from me, I'll post it.  Just let me know.

[DhannielM_Intel]

Hello hpetrus, 

Thank you for reaching out to the community. I want to clarify that since you are using a Eurocom laptop, which is an Original Equipment Manufacturer (OEM) product, my ability to provide specific troubleshooting is limited. The BIOS settings are typically managed by the laptop's manufacturer. Therefore, if my suggestions do not resolve the issue, I recommend contacting Eurocom for further assistance.

To begin, please check for any firmware updates related to your laptop, as these may address CPU performance issues. Additionally, consider resetting your BIOS settings to their default values to undo any changes that might be affecting performance.

To assist further, could you please answer the following questions:

1. Have you checked if there are any BIOS settings that might be affecting the turbo mode?
2. Have there been any recent changes to your system's power management settings?
3. Can you confirm if the issue persists across different Linux distributions or kernel versions?
4. Have you monitored CPU temperatures to ensure they are within normal operating ranges?

Best regards,

Dhanniel M.

Intel Customer Support Technician

[hpetrus]

Hi Dhanniel,

1.  BIOS settings are the same as always.  Secure boot is off, as well, as it always has been on this system.  Nothing here has changed.

2.  Power management settings are the same, as always.  Nothing has changed.

3.  I can confirm that the problem persists with previous Linux kernel verions.  Currently, I'm using 6.14.6.  I can confirm the problem persists going all the way back to 6.12 lts series.

4.  CPU temps are well within normal ranges on normal tasks, ranging from 40 deg C to 56 deg C on regular workloads.

Laptop BIOS is the most current for this OEM.  And, as I said, things were working perfectly well until a few days ago.  The situation appeared out of nowhere.

This issue is major for me because the laptop isn't even a year old, I bought it for on-set graphics power, and now it's virtually useless without the full turbo boost.  No one in the Linux community has been able to help, either (thus far).

What's going on is I don't have permissions - even as root - to change the no_turbo value from 1 (turn on no_turbo) to 0 (turn off no_turbo).  I can neither do it manually, nor with tuned, throttled, or cpupower.

I was able to get it to work on a live USB key, but once installed on the system, I can't.

I really need help here.

[DhannielM_Intel]

Hello hpetrus, 

Have you had the opportunity to test the system using a different Linux operating system to see if the issue persists? Additionally, could you confirm whether the live USB key you used is running the same version of Arch Linux as your installed system?

Best regards,

Dhanniel M.

Intel Customer Support Technician

[hpetrus]

Yes, I have tried other Linux flavours.  What's most interesting is that the Arch Linux 2025.05.01 live media doesn't have the problem (it's kernel is 6.14.4).  But, as soon as it's installed using pactrap, and it installs with the latest kernel - currently 6.14.6 - the problem exists.

Downgrading the kernel - even to the 6.12.x LTS - doesn't solve the problem, however.  I've downgraded ucode, as well as linux-firmware and linux-firmware-whence (not all together, however) the problem doesn't go away.

As I mentioned before:  the BIOS settings worked fine previous to this problem.  I've reset the BIOS, but still the problem persists.

This problem appeared suddenly after an update, but it's unclear as to what exactly it is.

I know that I'm not the only one experiencing this problem:

https://www.reddit.com/r/linuxquestions/comments/zlmwyn/intel_turbo_boost_will_not_work_in_any_distro_ive/

There are others here and there, as well.  It seems in at least one other case I've heard about, there is an over-simplified Insyde BIOS involved, as is the case I'm experiencing.  In other words, there are no fine-tuning switches and options for turbo, RAM tuning, Thunderbolt controls, etc.  Just an over-simplified Overclocking option that shows nothing of what's happening under the hood.  My guess is that this has something to do with it.  However, as I mentioned before, I could turn on turbo boost by hand before with

sudo -i

echo 0 > /sys/devices/system/cpu/intel_pstate/no_turbo

Now, I get an 'Operation not permitted.'  Obviously because the BIOS is reporting turbo as off, but there's no obvious option to fix the issue in-BIOS.

[DhannielM_Intel]

Hello hpetrus, 

Thank you for sharing this information with me. I will take the time to investigate further and provide you with an update as soon as possible.

Best regards,

Dhanniel M.

Intel Customer Support Technician

[DhannielM_Intel]

Hello hpetrus, 

Thank you for your patience. After reviewing the latest kernel update, could you please confirm whether this issue persists in version 6.14.7?

Best regards,

Dhanniel M.

Intel Customer Support Technician

[hpetrus]

Hi Dhanniel —

Yes, the problem persists with 6.14.7.

I should remind you that the Arch live media does not exhibit this problem.  Once it's installed on the drive, the problem shows up.  The live media features 6.14.4.  However, downgrading the installed OS to 6.14.4 still exhibits the same problem.  Most unusual.

[DhannielM_Intel]

Hello hpetrus, 

Thank you for confirming. I’ll continue investigating and will keep you updated as soon as I have more information.

Best regards,

Dhanniel M.

Intel Customer Support Technician

[DhannielM_Intel]

Hello hpetrus, 

Thank you for your patience. After further investigation, it seems the issue you're experiencing is related to firmware-level restrictions imposed by your laptop's BIOS or Embedded Controller (EC).

Here's what I've found after reviewing the thread and conducting a thorough investigation:

• You've mentioned that the issue occurs across different Linux distributions, and persists across all kernel versions, indicating it's not related to microcode or configuration.
• The problem doesn't appear when using a live USB, but occurs when the OS is installed on the drives. This suggests that Turbo Boost functions correctly and the CPU is capable of boosting.
• Additionally, you've noted receiving an "Operation not permitted" message, which indicates that the system firmware is enforcing this limit.

This behavior is common in high-performance mobile CPUs, such as the i9-14900HX, where OEMs enforce strict platform-level power and thermal policies that can disable Turbo Boost if certain thresholds are detected or locked by the EC.

Here are my recommendations, though I strongly advise discussing these with your OEM engineers before proceeding:

• Perform a full EC reset using the power drain method.
• Check and set the platform_profile to performance.
• Verify firmware power policies.
• If necessary, perform a full BIOS recovery flash, rather than just a standard update.

Lastly, contacting your OEM engineers is the best course of action, as this appears to be a platform policy lock rather than a defect in the processor or Linux OS.

Best regards,

Dhanniel M.

Intel Customer Support Technician

[DhannielM_Intel]

Hello hpetrus, 

I wanted to follow up to ensure you've seen my previous response. Our investigation suggests that the issue may be related to firmware restrictions specific to your laptop. Therefore, I recommend contacting the manufacturer's support team directly for further assistance, as they will be best equipped to address firmware-related concerns.

As this matter pertains to your laptop's firmware, I will be closing this inquiry. Should you need additional support in the future, please feel free to submit a new question. Please note that this thread will no longer be monitored. Thank you for your understanding.

Best regards,

Dhanniel M.

Intel Customer Support Technician

[hpetrus]

I guess this is all you can do, for now.  My vendor is on top of modifying the BIOS, as I wait impatiently to see if my laptop is truly useless or not.

Thanks, Dhanniel.

[formigoni]

Hey! I also have this issue with an i5-1235U, I managed to fix this with a combination of package downgrades:

- intel-ucode 20250211-1

- linux-firmware 20250311

- linux-lts 6.12.21-1

- sof-firmware 2025.01.1-1

I also had this error:

> echo 0 > /sys/devices/system/cpu/intel_pstate/no_turbo

 'Operation not permitted.'

But now it works out of the box. This is a bug in the kernel or intel-ucode.

Another workaround to avoid using outdated packages is to disable intel pstate, in /etc/default/grub change the 'GRUB_CMDLINE_LINUX' to include 'intel_pstate=disable', this will enable 'acpi_cpufreq' instead.

[hpetrus]

INTEL PEOPLE:  If you're reading this, please look closely at @formigoni 's post above.  I can confirm that that is the case and downgrading does work, but that I have to turn off `/sys/devices/system/cpu/intel_pstate/no_turbo` after boot (BIOS settings are ignored by intel_pstate) for turbo to kick in.  I believe this bit provides a big hint to the team.  I would imagine that the issue is prevalent on laptop CPUs, due to laptop BIOSes being locked (turbo modes and OC tweaks hidden behind a single 'Boost Performance' setting).  Your recent kernel modules and/or ucode - since early May '25 - have become sensitive to certain BIOSes.  Please, look into it again to perhaps add a work-around to these corner cases.

I, too, discovered a while back that suppressing intel-pstate as a kernel parameter and turning on acpi_cpufreq provided an improvement, but the frequencies are not to the specs of what this processor can deliver.  For example, one thread will peak at 5.2GHz, but all of the others go no further than 2.4GHz.  A massive improvement over the failing intel_pstate, which only allows base clock speeds of 2.2GHz on the high perf cores and 1.6GHz on all the others.  When intel_pstate was working correctly, I would get 5.8GHz on the hi-perf cores and 4.3GHz on the rest.  I've never been jealous of my children's laptop CPU performances before this.  So, this is what it feels like. 

@formigoni  thanks for your reply and for sharing your path to success (by stepping backwards).