On numerous occasions I’ve had customers complain about intermittent SQL Server performance only to find that the root cause was not the workload generated by the SQL Server VM but that the VMware environment was oversubscribed and was not providing sufficient CPU resources to the SQL Server when required.

In most cases I was able to quickly identify this issue by checking the VMware CPU Ready counter, converting it to a percentage (see calculation here) and using the CPU Ready threshold tables here to determine if the percentage is high for the number of vCPUs presented.

This article (High CPU Ready, Poor Performance here) goes through a similar scenario and provides some great insight on what to look for and even some other ways to capture and analyse the CPU Ready {2ec0bbd3bfdf207d2f0779c26660c3798ccadae611e41b6dbc787103c4a85cdd} (see ESXTOP Batch Mode Analysis with Window Performance here)