Intel Core i5 8400 's Advantages
Lower TDP (65W vs 125W)
Intel Core i9 10900K 's Advantages
Released 2 years and 7 months late
Higher specification of memory (2933 vs 2666)
Larger memory bandwidth (45.8GB/s vs 41.6GB/s)
Higher base frequency (3.7GHz vs 2.8GHz)
Larger L3 cache size (20MB vs 9MB)