Slow connector/adapter entity searches, neither SQL nor Unify.Service.Connect are consuming excessive CPU or memory

On various connectors and adapters with ~40,000 entities I see slow performance in the Entity Search screen - typically approximately 30 seconds to refresh and display 10 records.

This performance is consistent regardless of whether a filter is set or not - same speed even when showing just one record.

After stopped the Broker service and rebuilding all SQL table indexes there was no change in performance.

The SQL server and Broker service are on the same server, which is a VM with 4 vCPUs and 16GB of memory.  SQL is using 8GB of memory and Broker ranges from 200MB to 1GB depending on what it is processing at the time.  Entity Search performance is the same regardless of whether or not the Scheduler is enabled or disabled.

While the Entity Search screen is refreshing, SQL uses around 5-10% of CPU, and Unify.Service.Connect similarly uses around 5-10% of CPU, and the system CPU is mostly idle.  Disk activity jumps from a background maximum of around 100KB/sec to a consistent 10MB/sec while the Entity Search screen is refreshing, so this would appear to be at the root of the issue.

Do you have any suggestions how the system might be tuned to improve performance?