A Look At The Windows vs. Linux Scaling Performance Up To 64 Threads With The AMD 2990WX
On relative terms, in Blender Windows was actually scaling better relative to the 4-thread configuration but Linux was offering much better raw performance.
With the Java-based Sunflow rendering benchmark on the CPU, this benchmark actually ran faster on Windows at the lower thread counts. At 24 threads is where Windows and Linux were performing about the same while at greater than 24 threads is where Linux 4.18 on Ubuntu 18.04 LTS was yielding faster performance.
The proprietary V-RAY was scaling fine on both operating systems up to 64 threads at least and around a 7x increase from four to sixty-four threads.