Virtualized applications can be one of the most performance-intensive workloads in the datacenter. While first-generation hypervisors may have encountered performance issues when hosting XenDesktop shared desktops, XenServer offers specific performance and efficiency optimizations that let you include virtualized applications in your datacenter consolidation projects without compromising on the experience you deliver.

Storage efficiency is central to the TCO of any virtualization deployment. IntelliCache lowers the cost of XenDesktop VDI deployments by making intelligent use of local storage. The first time a shared virtual desktop VM is booted on the host, IntelliCache keeps a copy of the disk image on the local disk. Subsequent virtual desktop VMs on the host reference this locally-cached copy of the virtual disk image, lowering the IOPS requirement on centralized storage up to 95 percent. By enabling lower-cost, lower-specification storage to be used for the centralized storage system, IntelliCache yields typical savings in an overall XenDesktop deployment of 15 – 35 percent. Future enhancements to IntelliCache will optimize total deployment costs even further.

XenServer is the industry's hypervisor to support OpenFlow, a revolutionary network technology designed to virtualize datacenter networks in the way x86 server virtualization has virtualized Windows and Linux workloads. XenServer also includes the Open vSwitch, an open source technology which offers powerful security and network visibility capabilities for XenDesktop deployments. For example, Access control (ACL) policies can be configured for virtual desktop workloads to control user access to certain network services, such an Internet radio service which could result in performance degradation for the virtual desktop environment. Tools like RSPAN and integration with third-party NetFlow collectors give network administrators better visibility into virtual networks for troubleshooting and reporting.

Dynamic Memory lets you pool available physical memory on the host and dynamically allocate it to virtual machines based on workload needs. By enabling more efficient usage of physical memory resources, Dynamic Memory allows more VMs to be running simultaneously on a virtualization host without noticeable performance impact, reducing the number of hypervisor-capable servers needed to host large numbers of virtual desktops.

Microsoft RemoteFX, a feature of the Remote Desktop Services (RDS) server role, lets you provide users with a rich user experience when accessing virtual desktops from a broad range of endpoint devices. For example, using RemoteFX in a VDI-based desktop environment, users can work remotely in a Windows Aero desktop environment, watch full-motion video, enjoy Silverlight animations and even run 3D applications from any endpoint device.

By using Citrix and Microsoft for desktop virtualization, you can leverage the enhanced VM density capabilities of Microsoft Hyper-V 2008 R2 SP1 to provide users with the rich experience of Windows 7 using Remote FX while enabling IT to securely manage both physical and virtual infrastructures using System Center. Integrated with Windows Server 2008 R2 and System Center management capabilities, and complemented with partner technology from Citrix, Microsoft Hyper-V 2008 R2 SP1 delivers unique end-to-end business value for desktop virtualization.

XenDesktop utilizes the Memory Overhead functionality in vSphere 5, which enables administrators to dedicate less memory per desktop by enabling multiple desktops to "borrow" memory when they experience memory resource constraints.

New network I/O controls let different XenDesktop VMs sit in multiple resource pools and be given a higher or lower share of bandwidth than the others so you can create QOS-like bandwidth limits.

VMware's new vSphere® Storage Appliance is highly optimized for Citrix XenDesktop FlexCast provisioning. Combined with the new NFS support for Storage I/O Control and storage DRS in vSphere, this can improve data storage and retrieval by up to 20 percent while providing a one-stop shop for virtual desktop image and data management, business continuity and disaster recovery.