Intel Core i7 9750H 's Advantages
Higher base frequency (2.6GHz vs 2.3GHz)
Lower TDP (45W vs 55W)
Intel Core i9 12900HX 's Advantages
Released 3 years and 1 months late
Better graphics card performance
Higher specification of memory (4800 vs 2666)
Larger memory bandwidth (76.8GB/s vs 41.8GB/s)
Newer PCIe version (5.0 vs 3.0)
Larger L3 cache size (30MB vs 12MB)
More modern manufacturing process (10nm vs 14nm)