Intel Core i5 9400 's Advantages
Released 2 years late
Higher specification of memory (2666 vs 2400)
Larger memory bandwidth (41.6GB/s vs 38.4GB/s)
Larger L3 cache size (9MB vs 3MB)
Intel Core i3 7100T 's Advantages
Better graphics card performance
Higher base frequency (3.4GHz vs 2.9GHz)
Lower TDP (35W vs 65W)