3 Replies Latest reply on Jul 16, 2018 5:59 PM by Intel Corporation

    i7-8750H power trottling


      Hello everyone,


      I've recently bought an Asus FX504GE with the following specifications:

      Core i7-8750H

      16 GB of DDR4 2666 MHz in dual channel.

      Nvidia 1050 Ti 4 GB GDDR5

      128 GB M.2 drive and 1 TB 5400 RPM mechanical drive.



      Let me see if I understand how is this processor supposed to work, please let me know if i I'm wrong with any of the points.


           - It should be able to keep working at 45 W for any given time without risking it to damage so long the temperatures do not exceed 100 Celsius which is the max rated temperature.

           - It should be able to reach 4.1 GHz on a single core or 3.9 GHz on all 6 cores while temperatures allow or for the maximum duration of the boost window or in case temperatures do not allow it should lower clock anywhere from 3.9 GHz to 2.2 GHz.

           - Boost frequency should be enabled once there is a spike or higher demand of computational power.

           - TDP and boost frequency work like that for any processor (counting on it having Turbo Boost) regardless of the series of the processor H, U, Y, Xeon, etc.


      The issue I'm having is the following: The CPU is constantly being limited to just 25 W even thought this is a 45 W part and temperatures are at a relatively low 70 - 73 Celsius. I've already contacted Asus on this regard an they insist it is a normal behavior, to which I don't agree.


      Here are some results of stress testing Using AIDA 64


      Even though the CPU was used at 100% power never was more than 26 W, clock speed was keep at a steady 2.22 GHz on all cores and turbo boost never kicked in, and finally temperatures never went above 60 Celsius. On other scenarios CPU speed could reach more the the base 2.2 GHz but the power limit is keep at 25 W no matter what.




      Running CineBench R15 just corroborates the situation as this PC is only scoring a mediocre 700 points maybe 800 in the best case, usually 2nd and 3rd test give better results as more or less 1/3 trough the test it can go full 45 W and scores could reach somewhere in the 1000, To measure power consumption I used XTU




      Using XTU to stress test the CPU It is possible to achieve full power (bouncing from 41 to 46 W) and frequencies from from 3.5 GHz up to 3.9 GHz. For some reason It is the only test in which this is possible from the start, and can keep such demands without any issues for 15 minutes or more.





      I've had my PC plugged during the rests, power plan is set to high performance, BIOS is up to date and there is no setting I can change to enable or disable power limitation, I've done a factory reset and even a clean Windows installation and still no luck.

      I've tried with Asus support who insist this is a "normal behavior" and "it is to prevent damage on the CPU" which I don't believe at all, maybe i'm wrong that is why I'm here now, to me it is more of a BIOS lock they have on this PC either because the cooling system is not that great or perhaps the VRMs are of a cheaper quality. I've also done some undervolting 130 mV and it helps with temperatures and clocks but it does not lift the 25 W limitation. Also some Posts on the internet regarding this particular model https://linustechtips.com/main/topic/934169-i7-8750h-power-limit-throttling-low-tdp-even-though-cooling-is-capable/ and Just got this today, so I have to share with you guys ... | TechPowerUp Forums and even a review ASUS TUF FX504 Gaming Laptop Review and Benchmarks - YouTube mention the 25 W limitation I'm facing, this ultimately leads me to believe it is an issue with the computer it self rather than the CPU which is what Asus says.





      Tank you and hoping to hear from you soon.



        • 1. Re: i7-8750H power trottling
          Intel Corporation
          This message was posted on behalf of Intel Corporation

          Hello qazwsx_741
          Thank you for joining the community.
          Reviewing the information that you have provided I see that your Intel® Core™ i7-8750H Processor is working as expected on the system due to is not going over the speed or the temperature recommended on the product specifications (https://ark.intel.com/products/134906/Intel-Core-i7-8750H-Processor-9M-Cache-up-to-4_10-GHz?q=i7-8750H), continuing on with the topic of the speed and temperature it would increase depending on the system workflow only when is needed. I see that you have contacted the system manufacturer (ASUS*) to consult this situation and you have been advised that the system is working under the expected behavior.
          In case you are facing a BIOS/firmware limitation as you motioned this should be better handle with ASUS* to work on the case.
          Leonardo C.

          • 2. Re: i7-8750H power trottling

            Thanks Leonardo C for your reply


            I haven't had any issues with temperature and clock speeds are on the 2.2 GHz to 4.1 GHz indeed everything is under the provided specifications. During light light usage the CPU has no issue going all the way up to 3.9 GHz on all cores and keep that speed, and the single core speed turbo is close to 4.1 GHz.  My real issue is that although it is working under specifications I don't believe it is working at is potential or at full performance, please correct me if i'm wrong.



            Let me see if I can better explain what I'm facing on this PC. During light use I don't have issues everything works as expected, temperatures are low, and power consumption and clock speeds go up and down depending on the compute demand. The problem begins when I start using more CPU demanding tasks like video conversion or video editing where the supplied power to the CPU if limited to just 25 W, meaning the CPU is not able to rise its clock speeds as high to keep up with the demand. Another example is stress testing (I'm aware it isn't a real world scenario) where CPU usage is pretty much 100%, yet , Turbo Boost wasn't enabled even once and CPU speed was locked at 2.2 GHz and I really mean locked, not the slightest variation. (Turbo boost on the BIOS is enabled by the way)  To make things more weird CPU temperature is stable at 63 Celsius, far from the max temperature. In this case I would have expected the possessor to increase its speed to comply with the compute demand and frequency to go up and down, but, it doesn't because it is power throttling at 25 W, no more power is supplied to the CPU, maybe I'm not understanding how the 45 W limit works.

            I've tried with different programs and its still being limited to just 25 W, whether it is 2.2 GHz and 100% CPU usage or any higher speed and less CPU usage power never goes beyond 25 W. This is the thing I don't believe is working as it should.




            • 3. Re: i7-8750H power trottling
              Intel Corporation
              This message was posted on behalf of Intel Corporation

              Hello qazwsx_741

              Thank you for your response.
              Looking in to the information about the processor specifications the TDP 45W it refers to Thermal Design Power: represents the average power, in watts, the processor dissipates when operating at Base Frequency with all cores active under an Intel-defined, high-complexity workload and referring to the Configurable TDP-down it refers to the processor operating mode where the processor behavior and performance is modified by lowering TDP and the processor frequency to fixed points. The use of Configurable TDP-down is typically executed by the system manufacturer to optimize power and performance.
              In this case, if the limitation is set on the system built I recommend to verify the configuration with ASUS*.
              Leonardo C.