Phoronix published A Look At The Windows vs. Linux Scaling Performance Up To 64 Threads With The AMD 2990WX A quote from the article:

This past week we looked at the Windows 10 vs. Linux performance for AMD's just-launched Ryzen Threadripper 2990WX and given the interest from that then ran some Windows Server benchmarks to see if the performance of this 64-thread CPU would be more competitive to Linux. From those Windows vs. Linux tests there has been much speculation that the performance disparity is due to Windows scheduler being less optimized for high core/thread count processors and its NUMA awareness being less vetted than the Linux kernel. For getting a better idea, here are benchmarks of Windows Server 2019 preview versus Ubuntu Linux when testing varying thread/core counts for the AMD Threadripper 2990WX.

 A Look At The Windows vs. Linux Scaling Performance Up To 64 Threads With The AMD 2990WX