Performance Charts do not limit percent values to 100%.

Products

• VMware vSphere ESXi

Issue/Introduction

This article documents a change in behavior from 7.x to 8.x in the UI where it displays the actual used% as opposed to capping the used% at 100.

Environment

VMware vSphere ESXi 7.x, 8.x

Cause

The virtual machine > monitor > performance > performance overview has a known issue with the graph. The MHz on the right of the graph is the same reporting for the Percentage (%) on the left of the graph.
This graph includes the 16 cores not 8 vCPU's. 

Resolution

It is possible for CPU usage and VM usage to be over 100%, due to turbo boost. For VM usage, it can also go above100% (assuming based on the total number of vCPUs) because of the CPU from IO threads. Due to this, it removes the unnecessary artificial limits on some of the counters ("cpu.usage" and "cpu.usagemhz" are based on "cpu.used", which effectively is already measured in TCs (timer cycles) on VMkernel level, which means that for higher core frequency we are going to receive more TCs (in microseconds) for the same time-interval).

VMs CPU load graph can exceed 100% which was previously limited to 100%. When VMs CPU usage exceeds 100%, performance graphs no longer show CPU usage in percentage - vCenter UI > VM performance in vCenter > VM > Monitor > Performance.
Receiving alerts about high CPU usage in VMs and ESXi hosts.

Use the virtual machine > monitor > performance > advanced to see the correct CPU usage of the virtual machine.
This graph includes the 16 cores and not 8 vCPU's.

Additional Information

The warning Alarm Triggered in the vCenter with the CPU Utilization