Intel Core i5 12400 's Advantages
Lower TDP (65W vs 120W)
AMD Ryzen 9 9900X3D 's Advantages
Released 2 years and 8 months late
Higher specification of memory (5600 vs 4800)
Larger memory bandwidth (89.6GB/s vs 76.8GB/s)
Higher base frequency (4.4GHz vs 2.5GHz)
Larger L3 cache size (128MB vs 18MB)
More modern manufacturing process (4nm vs 10nm)