GPU mining requires very little CPU resources so it is not unusual to consider mining a CPU friendly coin. I have an I7 4770 too and mine Zcoin on it while using the GPU’s for Zcash. When CPU mining I usually specify in the configuration one less CPU/thread than is supported by the processor to make sure there is no delay in CPU access for the GPU mining or any other activities on the machine. They other alternative is to lower the priority of the CPU mining task but it’s not easy to automate configuring the priority each time it starts.