The column, NHN identifies the current Numa Home Node, which in Machine2 case is Numa node 0. You might want to disable other fields to reduce the amount of information on your screen. Use V (capital v) to display on VM worlds only. Open the console, run ESXTOP, press M for memory view. When reviewing the memory configuration of the virtual machine in ESXTOP we can deduct that its running on a single physical CPU using 4 cores on that die. Providing 4 vCPUs to the virtual machine ensures me that it will fit inside a single NUMA node. The host running the virtual machine is a dual socket quad core machine with HT enabled. To verify that the sockets have no impact on the NUMA scheduler I powered up a new virtual machine and configured it with two sockets with each 2 cores. For more information about NUMA please read the article: “ Sizing VMs and NUMA nodes” Although it’s a not covering the most current vSphere release, the basics remain the same. The vCPUs of a virtual machine are grouped in a NUMA client and this NUMA client is scheduled on a physical NUMA node. When a virtual machine powers on in a NUMA system, it is assigned a home node where memory is preferentially allocated. Socket configurations are transparent for the VMkernel When a CPU instruction leaves the virtual machine it gets picked up by a vCPU VMM world. For each vCPU the VMkernel schedules a VMM world. When a CPU instruction leaves the virtual machine it get picked up the Vmkernel. The light blue box shows the configuration the virtual machine presents to the guest OS. Lets use the example of 2 virtual socket 2 virtual core configuration. The virtual machine vCPU configuration is the sum of number of cores x number of sockets.
The VMkernel schedules a Virtual Machine Monitor (VMM) for every vCPU.
When you run a operating system it detects the hardware (layout) within the virtual machine.
#Does processor matter for os x vm software
Virtual socket and virtual socket are “constructs” presented upstream to the tightly isolated software container which we call a virtual machine. (Other than the number of usuable vCPU of course).Īnd its because of the power of the abstraction layer. No! There is no performance impact between using virtual cores or virtual sockets. Ok so it worked, now the big question, will it make a difference to use multiple sockets or one socket? How will the Vmkernel utilize the physical cores? Might it impact any NUMA configuration. I proceeded to power-on the virtual machine: I reconfigured the virtual machine to present 8 vCPU using a single socket and 8 number of cores per socket.
#Does processor matter for os x vm windows
When reviewing the cpu configuration inside the Guest OS, the task manager shows 4 CPUs:Ī final check by opening windows task manager verified it only uses 4 vCPUs. Just to show it works, I initially equipped the VM running Windows 2008 standard with 8 vCPU each presented as a single core. With this change you can for example configure the virtual machine with 1 virtual sockets and 8 cores per socket allowing the operating system to use 8 vCPUs. To solve the limitation of physical, VMware introduced the vCPU configuration options “virtual sockets” and “cores per socket”. Typically the OS-vendor only restricts the number of physical CPU and not the number of logical CPU (better know as cores).įor example, Windows 2008 standard is limited to 4 physical CPUs, and it will not utilize any additional vCPUs if you configure the virtual machine with more than 4 vCPUs.
In vSphere a vCPU is presented to the operating system as a single core cpu in a single socket, this limits the number of vCPUs that can be operating system. VMware introduced multi core virtual CPU in vSphere 4.1 to avoid socket restrictions used by operating systems. A question that I frequently receive is if there is a difference in virtual machine performance if the virtual machine is created with multiple cores instead of selecting multiple sockets?