Intel Core i9 12900 's Advantages
Released 3 years late
Higher specification of memory (4800 vs 2666)
Larger memory bandwidth (76.8GB/s vs 41.6GB/s)
Newer PCIe version (5 vs 3.0)
Larger L3 cache size (30MB vs 9MB)
More modern manufacturing process (10nm vs 14nm)
Intel Core i5 9400F 's Advantages
Higher base frequency (2.9GHz vs 2.4GHz)