Intel Core i5 11400 's Advantages
Higher base frequency (2.6GHz vs 2.5GHz)
Intel Core i5 12400 's Advantages
Released 10 months late
Higher specification of memory (DDR5-4800 vs DDR4-3200)
Larger memory bandwidth (76.8GB/s vs 50GB/s)
Newer PCIe version (5.0 vs 4.0)
Larger L3 cache size (18MB vs 12MB)
More modern manufacturing process (10nm vs 14nm)