Intel Core i5 8400T 's Advantages
Integrated graphics card
Higher base frequency (1.7GHz vs 1.1GHz)
Intel Core i9 14900T 's Advantages
Released 5 years and 9 months late
Higher specification of memory (DDR5-5600 vs DDR4-2666)
Larger memory bandwidth (89.6GB/s vs 41.6GB/s)
Newer PCIe version (5 vs 3.0)
Larger L3 cache size (36MB vs 9MB)
More modern manufacturing process (10nm vs 14nm)