Intel Core i5 7400 's Advantages
Integrated graphics card
Lower TDP (65W vs 140W)
Intel Core i9 7900X 's Advantages
Higher specification of memory (2666 vs 2400)
Larger memory bandwidth (79.47GB/s vs 35.76GB/s)
Higher base frequency (3.3GHz vs 3.0GHz)
Larger L3 cache size (14MB vs 6MB)