Intel Core i5 8400 's Advantages
Integrated graphics card
Lower TDP (65W vs 105W)
AMD Ryzen 7 5600X3D 's Advantages
Released 6 years and 3 months late
Higher specification of memory (3200 vs 2666)
Newer PCIe version (4.0 vs 3.0)
Higher base frequency (3.3GHz vs 2.8GHz)
Larger L3 cache size (96MB vs 9MB)
More modern manufacturing process (7nm vs 14nm)