Intel Core i9 9940X 's Advantages
Larger memory bandwidth (85GB/s vs 51.2GB/s)
Higher base frequency (3.3GHz vs 3.0GHz)
AMD Ryzen 9 5900 's Advantages
Released 2 years and 3 months late
Higher specification of memory (3200 vs 2666)
Newer PCIe version (4.0 vs 3.0)
Larger L3 cache size (32MB vs 20MB)
More modern manufacturing process (7nm vs 14nm)
Lower TDP (65W vs 165W)