Davoud Teimouri - Virtualization & Datacenter

A technology blog mainly focusing on virtualization and datacenter

VMCalc – Calculate CPU Ready

CPU Ready

As you may know, CPU ready is one of important metrics that you should consider them for deeper monitoring or troubleshooting performance issues on your machines.

CPU Ready Time is: how long is your virtual machine is waiting in line to use the CPU on the host?

There is some best practices about CPU Ready:

CPU Ready will calculate for each CPU and virtual machines CPU Ready must be divided to total of vCPUs on the machine.

CPU Ready is related to your CPU consolidation ratio, as example: You can assign 2:1 virtual CPU per physical CPU to your machine for achieve best performance and lower CPU Ready.

<5% CPU Ready
Generally No Problem!

5%-10% CPU Ready
Minimal contention that should be monitored during peak times

>10% CPU Ready
Contention to be investigated & addressed where the end user experience is being impacted.

Any Higher CPU ready will likely be impacting your users, and should be investigated.


You can calculate your CPU Ready from your real-time performance charts by the below formula:

(CPU summation value / (<chart default update interval in seconds> * 1000)) * 100 = CPU ready %

Check the below VMware KB:



VMCalc is a tools for CPU Ready and CPU Summation that it’s available on this LINK

You can calculate and convert CPU Ready and CPU summation very faster by this tools.


Davoud Teimouri is as a professional blogger, vExpert 2015-2016-2017, VCA, MCITP. This blog is started with simple posts and now, it has large following readers.

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Updated: March 17, 2017 — 2:11 pm

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Table of Contents Section 1. Introduction Section 2. CPU Section 2.1 Worlds and Groups Section 2.2 PCPUs Section 2.3 Global...