There are commonly 2 levels cache (L1, L2 cache) in multi-core processor architectures now with L2 cache shared for the cores. When the number of cores in the processor increases, the resource disputes in the L2 cache are very large, increased latency and memory access time. This paper recommends multi-core processor architecture with three-levels-cache organization (L1, L2 and L3 cache) in which L3 cache shares for cores. the authors rely on model of Multiclass Closed Product-Form Queuing Network (MCPFQN) to analyze and evaluate the performance of multi-core processor following the performance parameter (utilization, throughput, response times, etc.) in the L3 cache shared. By multithreading per core, the simulation results show that the performance of a multi-core processor is significantly enhanced.