Why use VDI, when I can use Terminal Services?

Working with Neocoretech NDV VDI solution, I see many advantages for using it over VMWare View or Citrix XenDesktop, due to the way it utilises RAM and negates the need for SAN solutions by using “Read only” desktops.  A common question when discussing virtual desktop solutions, is why use VDI when I can use Terminal Services. 

These points were addressed by Christophe Rettien, CTO of Neocoretech.

Architecture

• Neocoretech NDV is a 1:1 connection between 1 Thin Client and 1 Hosted PC (in this case a Virtual PC)
• Terminal Services is a 1:n connection between n Thin Clients and 1 Hosted Server (could be a physical virtual Server)

Protocol

• Neocoretech NDV is not tied to RDP and can use any available protocol including rich multimedia support, bi-directional sound and USB redirection. Available protocols are RDP, UXP, NX, RDP TCX...
• Terminal Services IS RDP so no protocol choice here. If Terminal Services does not provide sufficient performance, nothing can solve that!

Supported OSs

• Neocoretech NDV supports any x86 OS, which allows a user to run a Microsoft Windows XP, Windows 7 or Linux, with 32-bit or 64-bit distributions.
• Terminal Services is only supported by Microsoft servers, so the end user can run a remote session on a Windows 2003 or 2008 Server. Some tweaks exist to create a Windows 7 look and feel from a Windows 2008 session.

Supported Software

• Neocoretech NDV runs a single computer for each user, which means any application available on the OS used will be available to the user.
• Terminal Services runs multiple shared instances of a unique program within the same server (2003 or 2008) and only applications allowed to be shared are available to the end user.

Summary

Neocoretech NDV provides:

• Operating system choice
• All applications are supported
• Different applications installed according to user profile
• All protocols supported
• High availability options

NDV consequences:

• Requires powerful servers

Terminal Services provides:

• High density - good ratio server sizing/number of users

Terminal Services consequences:

• CAL licensing cost per session and per application
• Poor multimedia performance
• Complex GPO settings, if different desktops are to be presented based on user profiles (all applications need to be installed)

Conclusion

As with all solutions, it is more important to understand the requirement, rather than push a technology.  We need to understand when one solution would fit better than the other.

Terminal Services works well in environments with budget constraints or require a “vanilla” suite of applications.  VDI solutions such as Neocoretech NDV offer greater flexibility, management, operating system choice, supports a greater number of clients, and can be easily managed.