This message was posted on behalf of Intel Corporation
mezla: Thank you very much for joining the Intel® Processors communities. We will do our best in order to provide the information you are looking for.
Just to let you know, remember that altering clock frequency or voltage may damage or reduce the useful life of the processor and other system components, and may reduce system stability and performance. Product warranties may not apply if the processor is operated beyond its specifications, that is why we recommend to use the PC at stock settings.
On th elink below you will see the specifications of the processor:
Intel® Turbo Boost Max Technology 3.0 identifies the best performing core(s) on a processor and provides increased performance on those cores through increasing frequency as needed by taking advantage of power and thermal headroom:
Intel® Turbo Boost Technology dynamically increases the processor's frequency as needed by taking advantage of thermal and power headroom to give you a burst of speed when you need it, and increased energy efficiency when you don’t.
In regard to your question, the thing is that none of them will keep the frequency stable at 4.0GHz, because it will depend on the load of work, based on that the frequency will increase or decrease and in that case only by overclocking it you will be able to set the frequency at 4.0GHz.
Any further questions, please let me know.