By using virtual CPU (vCPU) overcommitment, you can have a setup where the sum of all vCPUs in virtual machines (VMs) running on a host exceeds the number of physical CPUs on the host.

You might experience performance deterioration when simultaneously running more cores in your VMs than are physically available on the host.

Best practices for vCPU overcommitment include the following:

• Assign the minimum amount of vCPUs required by the VM’s workloads for best performance.
• Avoid overcommitting vCPUs in production without extensive testing.
• If overcommitting vCPUs, the safe ratio is typically 5 vCPUs to 1 physical CPU for loads under 100%.
• It is not recommended to have more than 10 total allocated vCPUs per physical processor core.
• Monitor CPU usage to prevent performance degradation under heavy loads.