This section describes how to install and view VMware-specific performance data for virtual machines that run Microsoft Windows operating systems. VMware provides performance counters that enable you to view data on many aspects of guest operating system performance for the Microsoft Windows Perfmon utility.
Some virtualization processes dynamically allocate available resources depending on the status, or utilization rates, of virtual machines in the environment. This can make obtaining accurate information about the resource utilization (CPU utilization, in particular) of individual virtual machines, or applications running within virtual machines, difficult. VMware now provides virtual machine-specific performance counter libraries for the Windows Perfmon utility that enable application administrators to access accurate virtual machine resource utilization statistics from within the Windows Perfmon utility.
You can take advantage of virtualized CPU performance counters to use performance tuning tools inside the guest operating system. See the vSphere Virtual Machine Administration documentation.