6 cores / 12 threads, turbos to 4.7 Ghz. I don't see a problem there. What cooler is on it? Your PSU may be fine too, but knowing the exact model and age would help. In fact, list all your parts.
case:
thermaltake core p5 tempered glass titanium edition
motherbored:
Gigabyte z370 aorus ultra gaming 2.0 atx
cpu:
i7 8700k 4.3 ghz
Cpu cooler:
corsair hydro series h100x extreme performance liquid cpu cooler
memory:
16gb (2x8) Corsair vengeance 3200mhz
gpu:
righr now a msi 2080 ti gaming x trio
m.2:
250 GB Samsung 970 evo
HDD:
seagate barracuda 3TB SATA 3 5400 rpm
psu:
corsair RMx series RM750x (2018) 80 plus gold fully modular ATX psu
Operation system:
windows 10
had my system about 2 years now!