This message was posted on behalf of Intel Corporation1 of 1 people found this helpful
Thank you very much for taking the time to reach the Intel® Communities Team.
I understand you are facing some issues with the frequency of your processor which locks in 3.9 GHz when the CPU usage is 50%. Allow me to help you regarding this issue you are facing.
In this case, I would like you to verify the BIOS of your mainboard that the Intel® Turbo Boost Technology and the Intel® Speed Step features are activated. In addition, to make sure everything is fine with your processor, can you run the Intel® Processor Diagnostic Tool? Please share the results in your next post.
Furthermore, I would like to know which tool you are using to verify the usage and frequency of your processor. Is it the Windows * Task Manager or you are using another application?