Sony's Mark Cerny spoke in detail about the PlayStation 5's GPU, which is a custom designed AMD RDNA 2 chip. The PS5's GPU has a lower CU count than the Xbox Series X but has higher clocks and boosts differently compared to PCs and the Xbox. Sony intended to drive home the point that TFLOPs alone do not account for all the factors that collectively impact GPU performance.
https://www.notebookcheck.net/TFLOPs-aren-t-everything-The-PlayStation-5-s-10-3-TFLOP-GPU-is-a-custom-RDNA-2-part-with-36-CUs-running-at-2-23-GHz.458475.0.html