Searching for customer name in NAV 2015 is very slow

Hi,

We have two VMs, one with NAV 2015 and the other has SQL Server 2014, both on Windows Server 2012 R2.

I tested NAV 2015 from within the actual server itself, searching for a customer name in Order Processing -- Sales Order.

The system will show not responding for about a minute before displaying my results.

File transfer speed between servers shows average speed of about 110MB/s, 880Mbps.

Network speed utility like LanBench shows 2Gbps connection speed.

Network Adapter connection speed shows 10Gbps.

What could be the cause of this slow speed? Thank you.