Intel Core i3 8350K 's Advantages
Higher base frequency (4.0GHz vs 3.7GHz)
Lower TDP (91W vs 125W)
Intel Core i5 12600K 's Advantages
Released 4 years late
Better graphics card performance
Higher specification of memory (DDR5-4800 vs DDR4-2400)
Larger memory bandwidth (76.8GB/s vs 37.5GB/s)
Newer PCIe version (5.0 vs 3.0)
Larger L3 cache size (20MB vs 8MB)
More modern manufacturing process (10nm vs 14nm)