Intel Core i9 9900K 's Advantages
Higher base frequency (3.6GHz vs 3.5GHz)
Lower TDP (95W vs 125W)
Intel Core i9 11900K 's Advantages
Released 2 years and 5 months late
Better graphics card performance
Higher specification of memory (DDR4-3200 vs DDR4-2666)
Larger memory bandwidth (50GB/s vs 41.6GB/s)
Newer PCIe version (4.0 vs 3.0)