Intel Core i7 7820X 's Advantages
Higher base frequency (3.6GHz vs 3.5GHz)
Lower TDP (140W vs 165W)
Intel Core i9 9920X 's Advantages
Released 1 years and 5 months late
Larger memory bandwidth (85GB/s vs 79.47GB/s)
Larger L3 cache size (19MB vs 11MB)