Intel Core i5 12400 's Advantages
Released 6 years and 4 months late
Higher specification of memory (4800 vs 2133)
Larger memory bandwidth (76.8GB/s vs 34.1GB/s)
Newer PCIe version (5.0 vs 3.0)
Larger L3 cache size (18MB vs 6MB)
More modern manufacturing process (10nm vs 14nm)
Intel Core i5 6400 's Advantages
Higher base frequency (2.7GHz vs 2.5GHz)