Intel Core i5 9400 's Advantages
Higher specification of memory (2666 vs 2400)
Larger memory bandwidth (41.6GB/s vs 37.5GB/s)
Larger L3 cache size (9MB vs 8MB)
Intel Core i3 9300T 's Advantages
Higher base frequency (3.2GHz vs 2.9GHz)
Lower TDP (35W vs 65W)