you can choose kernel on grub menu
you can add
sudo mhwd-kernel -r linux65
sudo mhwd-kernel -i linux66
sudo mhwd-kernel -i linux67
about theses options , you can remove them
idle=nomwait processor.max_cstate=1 intel_idle.max_cstate=0
be careful linux67 may requiered nosplash if you have plymouth
quiet splash
also check for each kernel
cpupower frequency-info
it should be show amd-state
see this