You can increase performance of a virtual machine by making more processors available because more tasks can be performed simultaneously. When you assign a virtual processor to the virtual machine, it reduces the processor resources that are available to your Mac.

For Windows virtual machines running mostly office and Internet productivity applications, using multiple virtual processors is not beneficial, so the default single virtual processor is ideal. You can use multiple virtual processors in a virtual machine when the number of physical processor cores exceeds the desired number of virtual processors. For example, do not use two virtual processors unless you have a quad core physical processor.

Shut down or power off the virtual machine. You cannot change the setting while the virtual machine is powered on or suspended.


From the VMware Fusion menu bar, select Window > Virtual Machine Library.


Right-click the image of the virtual machine and click Settings.


In the Settings window, in the System Settings section, select Processors & Memory.


Select the number of processor cores for the virtual machine.


Restart the virtual machine.