Intel Core i5 8400 's Advantages
Integrated graphics card
Lower TDP (65W vs 250W)
AMD Ryzen Threadripper 2990WX 's Advantages
Released 10 months late
Higher specification of memory (2933 vs 2666)
Larger memory bandwidth (87.42GB/s vs 41.6GB/s)
Higher base frequency (3.0GHz vs 2.8GHz)
Larger L3 cache size (64MB vs 9MB)
More modern manufacturing process (12nm vs 14nm)