This message was posted on behalf of Intel Corporation
RodrigoCerviCutri: We will do our best to provide the information you are looking for.
As you mentioned, the processor Intel® i7-8086K supports up to DDR4-2666MHz of speed, that is the max speed we recommend to use in order not to harm the memory controller of the unit:
You can always get in contact with the manufacturer of the board to confirm if it is possible to increase the memory RAM speed, but when you use the memory RAM at a speed, in this case, higher than 2666Mhz, you will be forcing the processor to run at speeds it does not support and sooner or later the performance of the PC will be reduce and in the worst case scenario could get defective.
Intel Customer Support Technician
Under Contract to Intel Corporation