For larger multiprocessor and multi-socket systems, the correct configuration of Non-Uniform Memory Access (NUMA) settings can mean an increase in the performance of a single VM, of co-hosted VMs, and of an entire Hyper-V host.

NUMA is a computer system architecture used in multiprocessor systems, where some memory regions have smaller access latencies and others have greater access latencies. Each processor, for example, might have a portion of system memory connected to it that provides faster access, while other memory regions are accessed with greater latency. If the amount of memory dedicated to a processor spans the dedicated low-latency memory region, a processor must write and read from memory regions with a larger latency. With NUMA settings, you can ensure that the amount of memory reserved for a processor does not span the faster access regions.

If you align the sockets and nodes of a VM to the hardware a VM is running on, you can improve the VM performance. To match the virtual NUMA topology to the hardware topology, click the Use Hardware Topology button:

To allow virtual machines to span NUMA nodes, open the Hyper-V Manager and click Hyper-V settings in the menu on the left. Select NUMA Spanning from the left pane to configure the settings: