This post includes links to the resource pages related to Hardware Sizing for Microsoft Dynamics NAV
Microsoft Dynamics NAV 2013 R2 Sizing Guidelines for On-Premises Single Tenant Deployments
Microsoft Dynamics NAV 2013 R2 Sizing Guidelines for Multitenant Deployments White Paper
Microsoft Dynamics NAV 2013 R2 on Windows Azure White Paper
Thank you and Regards,
Tharanga Chandrasekara