Virtual Machine CPU Usage (%) Metric in Aria Operations displays values exceeding 100%

Products

• VMware Aria Operations (formerly vRealize Operations) 8.x

Issue/Introduction

• Following an upgrade to Aria Operations 8.18.4 or later, dashboards and reports may show CPU|Usage (%)  spikes exceeding 100% (up to 200% or more).
• Existing alerts based on a 100% threshold may trigger "false positives."
• Capacity planning reports may show critical over-utilization that does not align with legacy (pre-8.18.4) reporting.

Environment

VMware Aria Operations 8.18.4 and higher

Cause

The metric calculation uses the formula:

CPU Usage (%) = ( CPU|Usage (MHz) / CPU|Total Capacity (MHz) ) * 100

Because newer versions no longer cap the CPU|Usage (MHz) at the provisioned capacity, any demand exceeding the provisioned MHz (common on hosts with Turbo Boost enabled) will result in a value over 100%.

Resolution

This is an expected behavior.

Starting with VMware Aria Operations 8.18.4, the CPU Usage (%) metric was updated to more accurately reflect true resource demand. As a result, this metric is no longer artificially capped and can now display values greater than 100% (for example, due to host CPU Turbo Boost or ESXi kernel overhead).

Additional References: For more information on how this metric is calculated, please review the following documentation:

• Product Documentation: Virtual Machine Metrics: CPU | Usage (%)

• Broadcom KB:  CPU usage exceeds 100% in vSphere Performance Charts due to Turbo Boost

 

For use cases that require a metric that adheres to a 0–100% scale for standard reporting and capacity planning, it is recommended to transition to the CPU|Net Run (%) metric.

Validation Steps: To verify if a spike is due to the new calculation logic rather than a performance issue:

1. Compare CPU|Usage (%) with CPU|Net Run (%) at the same timestamp.
2. If CPU|Net Run (%) remains below 100% while CPU|Usage (%) exceeds it, the spike reflects high demand/Turbo Boost rather than a capacity breach.
3. Monitor the CPU Ready  contention to identify if the high demand is actually resulting in performance degradation.

Additional Information

Using %NETRUN as a primary metric for VM CPU rightsizing in Aria Operations

Japanese KB: Aria Operations の仮想マシン CPU Usage (%) メトリックが 100% を超える値を表示する