Intel Core i7 7800X 's Advantages
Higher base frequency (3.5GHz vs 3.0GHz)
Lower TDP (140W vs 165W)
Intel Core i9 9980XE 's Advantages
Released 1 years and 5 months late
Higher specification of memory (DDR4-2666 vs DDR4-2400)
Larger L3 cache size (25MB vs 8MB)