Observation
Some VMware CPU usage counters can exceed 100% because they are calculated against a baseline clock speed, not the processor’s actual operating frequency. Modern CPUs can temporarily operate at speeds above their base frequency using features like Intel Turbo Boost. When VMware measures utilization, it tracks timer cycles (TCs) at the VMkernel level. If the cores are running faster than the baseline, more cycles are observed in the same time interval, which pushes usage beyond 100%.
Starting in vSphere 8.x, VMware stopped capping these values at 100%, so charts now display the actual consumption, even if it exceeds 100%. This explains why, in performance graphs, you may see VM CPU usage exceed 100%, especially when multiple vCPUs and I/O threads are active.
Key points:
Performance charts no longer artificially limit percentages to 100%.
Usage % is based on baseline clock speed, so turbo frequencies raise the effective value.
VM CPU usage can exceed 100% due to vCPU scheduling and I/O thread activity.
In vSphere 8.0 U3, the graphs were updated to accurately display values beyond 100%, rather than flattening them at 100%.
In short, a value higher than 100% means the CPU is running above its baseline speed or extra cycles (from I/O threads or turbo boost) are being consumed, and VMware now reports this accurately rather than truncating it.
See the Broadcom article: