One of the primary benefits of the pending Rocket Lake-S series is the fact they're based on a new architecture, that architecture would offer better IPC. A website now has fired off tests at a Core i9 11900K measuring exactly that. 

The end result is that, although an IPC increase definitely is measured, Ryzen 5000 remains to be the faster architecture. IPC byw ie the number of instruction-by-clock, indicative performance per core. The asia based reviewer compares the Core i9 11900K with the Ryzen 9 5950 and that reveals the existing Ryzen 5000 chips are about 6% to 10% faster than the Rocket Lake processors when both architectures run at 4 GHz and are limited to four cores and eight threads. 

Leaked Benchmarks Indicate IPC Rocket Lake-S to be slower than AMD Ryzen 5000