You can change the number of virtual CPUs while your virtual machine is powered off. If virtual CPU hotplug is enabled, you can increase the number of virtual CPUs while the virtual machine is running.

About this task

Virtual CPU hot add is supported for virtual machines with multicore CPU support and ESXi 5.0 and later compatibility. When the virtual machine is turned on and CPU hot add is enabled, you can hot add virtual CPUs to running virtual machines. The number of CPUs that you add must be a multiple of the number of cores that exist on each socket.


When you configure your virtual machine for multicore virtual CPU settings, you must ensure that your configuration complies with the requirements of the guest operating system EULA.


  • If virtual CPU hot add is not enabled, turn off the virtual machine before adding virtual CPUs.

  • To hot add multicore CPUs, verify that the virtual machine is compatible with ESXi 5.0 and later.

  • Verify that you have the Virtual Machine > Configuration > Change CPU Count privilege.


  1. Click Virtual Machines in the VMware Host Client inventory.
  2. Right-click a virtual machine in the list and select Edit settings from the pop-up menu.
  3. On the Virtual Hardware tab, expand CPU, and select the number of cores from the CPU drop-down menu.
  4. Select the number of cores per socket from the Cores Per Socket drop-down menu.
  5. Click Save.