https://www.techpowerup.com/266442/core-i9-10900k-vs-ryzen-9-3950x-cinebench-r15-comparison-leaked Ahead of its launch a leaked ASUS ROG marketing slide reveals Cinebench R15 performance comparisons between the new Intel Core i9-10900K and AMD's current MSDT flagship part, the Ryzen 9 3950X. The graphs also include Intel's previous gen flagship, the i9-9900K, which should provide a reasonable indication of where the new Core i7-10700K performance could land.
In the single-threaded Cinebench R15 test, the Core i9-10900K scores 222 points, while the 3950X scores 213, which is a 4.22% lead for the new Intel flagship over AMD's. The i9-9900K is 2.81% faster than the 3950X in the same test. The landscape changes completely with multi-thread. Armed with 16 cores and 32 threads, the 3950X tests 48.61% faster than the i9-10900K, and a whopping 94.14% faster than the i9-9900K, which means the 3950X should land around 90% (±5%) faster than the i7-10700K. Core i9-10900K vs. Ryzen 9 3900X should make for a fascinating contest.
I guess the determining factor is cost.