Here's some Navi leaks. Take it with big boxes of salt.
Navi21
Up to 80 compute units/5120 GPU cores
A die size of around 505mm²
50% better performance per watt
https://hardwareleaks.com/2020/05/23/exclusive-future-amd-gpu-stack-navi21-navi10-refresh/
PC Specs: CPU: 7800X3D || GPU: Strix 4090 || RAM: 32GB DDR5 6000 || Main SSD: WD 2TB SN850