14900hx E-cores Thermal throttling first

[SevretaryNotSure]

I have aLenovo Legion 7i Pro 2x 2tb m.2 ssd, 32gb ram, i9-14900hx, rtx4090. Using HWinfo64 and Throttlestop I've noticed E-cores 12-15 spike within 5-7 seconds to 99-100⁰C ,when playing a game or running a benchmark, and stay there. This starts the thermal throttling process and heats up the cpu as a whole while the other cores are between 78-90⁰C. According to HWinfo64 these cores are throttled up to 56% during gameplay. To try and fix this I undervolted -80mV via XTU which gave me slightly better fps, but still thermal throttles a few seconds later. -80mV was the furthest i could go with -35mV P cache before BSOD's started. Is there a reason my E-cores are thermaling before my P-cores or is this normal? I haven't had this happen on any other computers.

[VonM_Intel]

Hi, SevretaryNotSure.

Your observations are valid, and what you're experiencing isn't entirely uncommon, though it may seem unusual given the advanced specs of your system. Throttling in Intel® Processors reduces clock speed when temperatures exceed TJ Max (or Tcase) to protect the processor and signal overheating. The Intel Core i9-14900HX uses a hybrid design with P-cores (performance cores) and E-cores (efficiency cores). E-cores, while efficient for lighter tasks, have less thermal headroom compared to P-cores. This could explain why your E-cores quickly reach 99-100°C under load. It might also be due to power or heat distribution, where P-cores handle heavier tasks and are cooled or throttled more effectively than E-cores. For self-built PC with Intel® Boxed Processors, ensure the following:

1. Make sure that the thermal solution being used is compatible and correct for the specific CPU.
   1. Refer to How to Choose Thermal Solutions for Intel® Core™ Boxed Desktop Processor.
   2. Refer to Information about Thermal Solutions
2. Verify proper installation of the processor thermal solution. Refer to the Cooler Installation section in Intel® Desktop Boxed Processors Support Videos and Instructions
3. Make sure to apply the right amount of thermal interface material (TIM).  
4. Check system fan operation.
5. Check air ventilation.

For laptops, refer to OEM since the OEMs decide the power/current limits. Any throttling happening there would be completely based on how the OEM designs the laptop. For overclocking: Note that the motherboard does have an impact on the ability to overclock. Some are better quality and more capable than others. Furthermore, the way the motherboard is set up also impacts the overclocking ability of a particular system (such as liquid cooler vs fan).

Have a nice day!

Best regards,

Von M.

Intel Customer Support Technician

[VonM_Intel]

Hello, SevretaryNotSure.

Have you had a chance to review my previous response? Please let us know if you require any further assistance. I'm here to help.

Best regards,

Von M.

Intel Customer Support Technician

[SevretaryNotSure]

Thanks for the replies Von. I ended up undervolting the cpu and p cache by -137mV, reduced the p-core boost to 5400mhz on up to 2 cores and 4700mhz for 8 cores, and set e-cores to 3600mhz. This paired with increasing PL 1&2 limits fixed the cooling problem while increasing cinebench from 29.6k to 33.4k. I don't thermal throttle anymore and temps stabilize around 85-92⁰C while gaming on ultra 1440p settings.

[MosesVette]

BRO.

I just wanted to take a moment to express my sincere gratitude for you posting this. It helped me more than you could imagine. I’ve been battling: high temps, thermal throttling and jet engine-level fan noise on my 4080 variant of the same device as you. I simply could not accept ''that's how these CPUs were designed'' but couldn't find any success anywhere undervolting it. Nothing worked for monthsssss. This post did though.

I literally created an account just to thank you, your help has been invaluable. Blessings to you, and I truly hope life brings you all the best. I’ll always be grateful for the insight you shared—it’s the little things man for real.

Take care brother. God bless you.

[VonM_Intel]

Hello, SevretaryNotSure.

Thank you for the update. It’s great to hear that undervolting the CPU and adjusting the cache, along with tweaking the core frequencies and PL limits, has resolved the cooling issue and improved your Cinebench score. It sounds like you've found a solid balance for performance and thermals. Achieving stable temps around 85-92°C while gaming at ultra 1440p settings is a great result, and it's good to know that you're no longer experiencing thermal throttling. 

I am glad to know you found a solution, thank you for taking the time to share this fix, and hopefully, it may help other community members experiencing similar behavior. Since the thread is now solved, I will proceed to close it. Please keep in mind that this thread will no longer be monitored by Intel.

Best regards,

Von M.

Intel Customer Support Technician