Intel Core i7 6900K 's Advantages
Larger memory bandwidth (76.8GB/s vs 41.6GB/s)
Larger L3 cache size (20MB vs 12MB)
Intel Core i7 9700K 's Advantages
Released 2 years and 5 months late
Integrated graphics card
Higher specification of memory (DDR4-2666 vs DDR4-2133)
Higher base frequency (3.6GHz vs 3.2GHz)
Lower TDP (95W vs 140W)