NAV 2015 memory issues (server)

Hi,

I have one client where the memory on the server (which runs NAV) keeps running out, its 8GB and scheduled to be upgraded to 16GB. Viewing task manager indicates that Microsoft.Dynamics.NAV.Server.exe is consuming by far the most memory. I have seen this up at 7000000 KB (7 GB). We have a number of clients on 2015 and they are not getting the same issue.

I can platform upgrade to the latest executables but would also like to know if this is a known issue that's been experience by others?

Thanks
Roddy