Today’s users expect and demand the full Windows
experience, even when they work in virtual environments. Windows Server
2012 delivers this experience better than ever before with enhancements
to RemoteFX, USB redirection, and the new User Profile Disks feature. This section introduces these new features and enhancements.
RemoteFX was first introduced in Windows Server 2008 R2 as a way of delivering a full Windows experience over the RDP across a wide variety of client devices. RemoteFX is part of the Remote
Desktop Services role service and is intended mainly for use in VDI
environments to support applications that use rich media, including 3-D
rendering. RemoteFX
uses two capabilities for providing remote users with a rich desktop
environment similar to the local desktop environment that PC users
enjoy:
-
Host side rendering Allows graphics to be rendered on the host instead of the client by utilizing the capabilities of a RemoteFX-capable graphics processing unit (GPU)
on the host. Once rendered on the host, graphics are delivered to the
client over RDP in an adaptive manner as compressed bitmap images. In
addition, multiple GPU cards are now supported on Windows Server 2012
as well as using a software GPU.
-
GPU Virtualization
Exposes a virtual graphics device to a virtual machine running on a
RemoteFX-capable host and allows multiple virtual desktops to share the
single GPU on the host.
RemoteFX can benefit organizations by enabling flexible work
scenarios like hot-desking and working from home. By making the virtual
desktop experience similar to that of traditional PCs, RemoteFX can
make VDI a more feasible solution for organizations who want increased
data security and simplified management of the desktop environment.
RemoteFX has been enhanced in Windows Server 2012 in a number of different ways, including the following:
-
RemoteFX is integrated throughout the RDS role services instead of
being installed as its own separate role service and is installed
automatically whenever the Remote Desktop Virtualization Host role
service is installed.
-
The performance when delivering streaming media content over RDP has been greatly improved.
-
RemoteFX can dynamically adapt to changing network conditions by using multiple codecs to optimize how content is delivered.
-
RemoteFX can choose between Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) to optimize performance when sending RDP traffic over the WAN (this is called RemoteFX for WAN).
-
Support for multi-touch gestures and manipulations in remote sessions is included.
-
Improved multimonitor support over RDP, which allows a virtual
machine to support up to four monitors regardless of their resolution,
is available.
-
There is now the ability to use VMConnect
to manage virtual machines that have the RemoteFX 3D Video Adapter
installed in them. (In the previous version of Windows Server, you had
to use a Remote Desktop connection to manage the virtual machines.)
To use RemoteFX, the host machine must:
-
Support hardware-assisted virtualization and data execution prevention (DEP)
-
Have at least one GPU listed as supporting RemoteFX in the Windows Server Catalog
-
Have a CPU that supports Second Level Address Translation (SLAT).
Note that Intel refers to SLAT as Extended Page Tables (EPT), whereas
AMD refers to SLAT as Nested Page Tables (NPT)
To configure a Windows Server 2012 host to use RemoteFX, you can use the new GPU management interface in the Hyper-V settings of the host (see Figure 1).
This interface lets you select from a list of available GPUs on the
host that are RemoteFX-capable (if any) and then enable or disable
RemoteFX functionality for the selected GPU. The interface also shows
the details concerning each RemoteFX-capable GPU on the host.
USB redirection in RemoteFX is an important ingredient in establishing parity of experience
between virtual desktops and traditional PCs. USB redirection was first
introduced in Windows 7 Service Pack 1 and Windows Server 2008 R2
Service Pack 1 to support RemoteFX VDI scenarios. USB redirection
occurs at the port protocol level and enables redirection of a wide
variety of different types of universal
serial bus (USB) devices, including printers, scanners, webcams, Voice
over Internet Protocol (VoIP) headsets, and biometric devices. USB
redirection does not require hardware drivers to be installed on the
virtual machines. Instead, the necessary drivers are installed on the
host.
In Windows 7 SP1 and Windows Server 2008 R2 SP1, RemoteFX USB redirection was supported only within virtual desktops running Remote
Desktop Virtualization Host. New in Windows Server 2012 and Windows 8
is support for USB redirection for Remote Desktop Session Host. This
enables new kinds of scenarios where RemoteFX can bring a richer
desktop experience for businesses that implement session virtualization
solutions.
Other enhancements to USB redirection in Windows Server 2012 include the following:
-
USB redirection for Remote Desktop Virtualization Host no longer requires installing the RemoteFX 3D Video Adapter on the virtual machine.
-
USB redirection for Remote Desktop Session Host is isolated
to the session in which the device is being redirected. This means that
users in one session will not be able to access USB devices redirected
in a different session.
