Intel Core i3 1215U 's Advantages
Better graphics card performance
Higher specification of memory (5200 vs 4800)
Lower TDP (15W vs 55W)
Intel Core i9 12900HX 's Advantages
Newer PCIe version (5.0 vs 4.0)
Higher base frequency (2.3GHz vs 1.2GHz)
Larger L3 cache size (30MB vs 10MB)