The FPS Review reviewed the AMD Ryzen 9 5900X vs Ryzen 9 3900X Performance
A quote from the article:
Introduction Today we are going to directly compare performance between the AMD Ryzen 9 3900X CPU known as Matisse and the AMD Ryzen 9 5900X CPU known as Vermeer. This is Zen 2 versus Zen 3, head-to-head 12-core to 12-core in the high-end desktop (HEDT) performance PC enthusiast realm for CPUs.AMD Ryzen 9 5900X vs Ryzen 9 3900X Performance Review