Intel Core i7 8086K 's Advantages
Higher base frequency (4.0GHz vs 3.6GHz)
Lower TDP (95W vs 125W)
Intel Core i7 12700K 's Advantages
Released 3 years and 4 months late
Better graphics card performance
Higher specification of memory (4800 vs 2666)
Larger memory bandwidth (76.8GB/s vs 41.6GB/s)
Newer PCIe version (5.0 vs 3.0)
Larger L3 cache size (25MB vs 12MB)
More modern manufacturing process (10nm vs 14nm)