Intel Core i5 9400H 's Advantages
Better graphics card performance
Higher base frequency (2.5GHz vs 2.4GHz)
Lower TDP (45W vs 55W)
Intel Core i5 12450HX 's Advantages
Released 3 years and 1 months late
Higher specification of memory (4800 vs 2666)
Larger memory bandwidth (76.8GB/s vs 41.8GB/s)
Newer PCIe version (5.0 vs 3.0)
Larger L3 cache size (12MB vs 8MB)
More modern manufacturing process (10nm vs 14nm)