You can add, change, or configure CPU resources to improve virtual machine performance. You can set most of the CPU parameters during virtual machine creation or after the guest operating system is installed. Some actions require you to power off the virtual machine before changing the settings.

Understanding the following concepts can help you plan your CPU resource allocation strategy.


The CPU or processor is the portion of a computer system that carries out the instructions of a computer program and is the primary element carrying out the computer's functions.


Comprises a logical execution unit containing an L1 cache and functional units needed to execute programs. Cores can independently execute programs or threads.


A process that does not have a full stack of memory associated for it. The thread is tied to a parent process. typically thread processes must run on the same computer, but can execute simultaneously on separate cores of the same node.


A physical connector on a computer motherboard that accepts a single physical chip. Many motherboards can have multiple sockets that can in turn accept multicore chips.

Resource sharing

Shares specify the relative priority or importance of a virtual machine or resource pool. If a virtual machine has twice as many shares of a resource as another virtual machine, it is entitled to consume twice as much of that resource when these two virtual machines are competing for resources.

Resource allocation

You can dynamically change resource allocation policies. For example, if at year end the workload on Accounting increases, you can increase the Accounting resource pool reserve.