What Eric has to Say about Virtual Machines Per Core. Eric Siebert has written an excellent article on SearchNetworking.com called “Sizing server hardware” which goes into “nuts and bolts” details for sizing virtual host server hardware. My 1 to 4 ration for VM density per logical CPU is my best practice but Eric goes into much more detail. Oct 19, 2017 · Management Operating System Best Practices for Performance. Prefer Hyper-V Server first, Windows Server Core second. Do not install any software, feature, or role in the management operating system that does not directly aid the virtual machines or the management operating system. Does Hyper-Threading affect Hyper-V? (Archived here.) A. The new four-core Intel Core i7 processor enables hyper-threading, which splits each processor core into two virtual cores to (potentially) improve performance. The concern with Hyper-V and hyper-threading is that you assign a number of processor cores to each virtual machine (VM).