At least 2 core CPUs are required to run a full node, at the minimum performance. If you are running on a private environment, with fewer transactions, then you will be fine with 4 CPU cores. So, the amount of network requests determines the CPU performance required to run the nodes. You will need to monitor your machine to decide the best requirements. In the PUBLIC NETWORK, TRON recommends to run a machine with at least 64 CPU cores for a Super Representative to become an approved applicant.