Intel Core i3 8300 's Advantages
Higher base frequency (3.7GHz vs 3.3GHz)
Lower TDP (62W vs 65W)
Intel Core i5 12600 's Advantages
Released 3 years and 9 months late
Better graphics card performance
Higher specification of memory (4800 vs 2400)
Larger memory bandwidth (76.8GB/s vs 37.5GB/s)
Newer PCIe version (5.0 vs 3.0)
Larger L3 cache size (18MB vs 8MB)
More modern manufacturing process (10nm vs 14nm)