A VMware vSphere 6.x Administrator sees the following output in esxtop:

What does the %RDY column represent?

A. CPU Cycle Wait Percentage

B. CPU Utilization

C. CPU Ready

D. Idle CPU Percentage

Explanation:

The percentage of time the world was ready to run.

A world in a run queue is waiting for CPU scheduler to let it run on a PCPU. %RDY accounts the percentage of this time. So, it is always smaller than 100%.

Reference: http://www.yellow-bricks.com/esxtop/