Well im probably not very accurate, but my old PC (intel 750 - 3GHz, from 2009) made material shader in 3-5s, but with ryzen its done in 1-2s.
Lightmass (that lowest / fastest option) - i compared my PC with one tutorial where guy opened project 2x faster and compiled code 2x faster (i think he have some kind of fast 4-core intel) but when it came to build lighting, my PC was faster around 2 - 2,5x. it took him maybe 1 minute but i was done it in 20-30s.
My comparison of CPUs is not good at all but im really satysfied with 8 core ryzen, i feel that speed when it comes to multi-core usage…
edit: im running ryzen only on 3 GHz and RAMs on 2133 MHz (3k mhz rams), i plan to overclock CPU and RAM too but im OC noob so i didnt found good tutorial yet how to OC it properly