Article has lots of pretty graphs and methodology but if you just want the numbers:

When taking the geometric mean of all the benchmarks ran on both operating systems, going from Microsoft Windows 11 Pro to Ubuntu 26.04 LTS meant +15.3% performance for the Ryzen 9 9950X3D2. Meanwhile with the Ryzen 9 9950X3D was +10.2% better performance on Linux. Or put another way, the Ryzen 9 9950X3D2 was less than 1% faster than the Ryzen 9 9950X3D in the same workloads on Windows 11 but under Ubuntu Linux this Dual Edition CPU was 5% faster than the Ryzen 9 9950X3D.