To verify if a connection from a remote computer that is running Windows 7 SP1 to a Windows Server 2012 (R2) backend with the RDP 8.x client you can follow these steps:

- Connect to Remote Desktop Services back-end offering RDP 8.0 (Windows Server 2012/2012 R2 or a Windows 8/8.1 VDI)
- Click on the connection quality button (looks like a wifi icon) 
- If the information dialog that appears says "The quality of the connection to the remote computer is excellent and UDP is enabled" then the connection is using RDP 8.x