Converting between CPU RDY summation and CPU % ready values

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2002181

To convert between the CPU ready summation value in vCenter's performance charts and the CPU ready % value that you see in esxtop, you must use a formula.
The formula requires you to know the default update intervals for the performance charts. These are the default update intervals for each chart:

• Realtime: 20 seconds
• Past Day: 5 minutes (300 seconds)
• Past Week: 30 minutes (1800 seconds)
• Past Month: 2 hours (7200 seconds)
• Past Year: 1 day (86400 seconds)

CPU ready %

To calculate the CPU ready % from the CPU ready summation value, use this formula:
(CPU summation value / ([chart default update interval in seconds] * 1000)) * 100 = CPU ready %
Example: The Realtime stats for a virtual machine in vCenter might have an average CPU ready summation value of 1000. Use the appropriate values with the formula to get the CPU ready %.
(1000 / (20s * 1000)) * 100 = 5% CPU ready

CPU ready summation value

To convert the CPU ready % into a CPU ready summation value, reverse the calculation and use this formula:
(CPU ready % / 100) * ([chart default update interval in seconds] * 1000 = CPU summation value
Example: If a virtual machine has a CPU ready % of 5m, its CPU ready summation value on the Realtime performance chart is calculated like this:
(5 / 100) * 20s * 1000 = 1000 CPU ready