—This work tries to derive ideas for thread allocation in Chip Multiprocessor (CMP)-based network processors performing general applications by Continuous-Time Markov Chain modeling and Petri net simulations. The concept of P-M ratio, where P and M indicate the computational and memory access overhead when processing a packet, is introduced and the relation to thread allocation is explored. Results indicate that the demand of threads in a processor diminishes rapidly as P-M ratio increases to 0.066, and decreases slowly afterwards. Observations from a certain P-M ratio can be applied to various software-hardware combinations having the same ratio.