# Help, my CPU clock speed stuck at the 3.9Ghz, and sometime it even drop into 3.1-3.7Ghz



## ok masterpiece (Jan 25, 2022)

This computer used to get 4.1 and can keep 4.0-4.1 without dropping when I'm playing games.

of course, it could keep 4.1 in the test, but it stuck at 3.9 now.

Moreover, when the computer is idle, the speed even can't keep at 4.0.


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## unclewebb (Jan 25, 2022)

ok masterpiece said:


> This computer used to get 4.1


Open Limit Reasons when stress testing and find out why your CPU is throttling. You will likely see TVB lighting up red in Limit Reasons This confirms that TVB throttling is in progress.  

If you want 4.1 GHz when fully loaded, try clearing the Thermal Velocity Boost box in the FIVR window. This supposed Intel boost feature does the opposite. When the Thermal Velocity Boost option is checked and enabled, the CPU will slow down 100 MHz when it reaches approximately 70°C. That appears to be why your CPU is only using the 40 multiplier when fully loaded. 



ok masterpiece said:


> when the computer is idle, the speed even can't keep at 4.0.


The CPU speed when a mobile CPU is idle is not important. At default settings, the individual cores will be rapidly entering and exiting various low power C states to keep your CPU cool. The low power C states also improve battery run time when running on battery power. If you want steadier MHz when idle, you can use ThrottleStop to disable all of the low power C states and you can also disable C1E. Disabling the C states will prevent Intel mobile CPUs from using the maximum turbo boost multipliers so I do not recommend doing this.  

If you want to see the difference this makes, open the C States window, check the C States - AC box, select the Off radio button and press the Apply button. The ThrottleStop C States monitoring table should now report that the C3, C6 and C7 C states are no longer being used. (0.0) 





You will need to clear the C1E box on the main screen to disable the C1E C state. To re-enable the C states do the opposite. Check the C States - AC box, select the On radio button and press the Apply button. Check C1E to re-enable C1E.


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## ok masterpiece (Jan 26, 2022)

unclewebb said:


> Open Limit Reasons when stress testing and find out why your CPU is throttling. You will likely see TVB lighting up red in Limit Reasons This confirms that TVB throttling is in progress.
> 
> If you want 4.1 GHz when fully loaded, try clearing the Thermal Velocity Boost box in the FIVR window. This supposed Intel boost feature does the opposite. When the Thermal Velocity Boost option is checked and enabled, the CPU will slow down 100 MHz when it reaches approximately 70°C. That appears to be why your CPU is only using the 40 multiplier when fully loaded.
> 
> ...


OMG， It works. Thanks so much


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