Executive Summary

VDI has the potential to revolutionize enterprise desktop computing by lowering the total cost of desktop computing, increasing security and compliance and making desktop computing more agile. Many companies have deployed VDI only to realize that their VDI architecture could not scale beyond a thousand desktops without either degrading desktop performance or requiring a massive additional investment in computing, networking or storage infrastructure. The VDI cost and performance challenges are a result of memory and storage bottlenecks that lower VDI density per server, degrade user performance and ultimately increase the cost of VDI. In order for VDI to achieve broad adoption, it must deliver cost, performance and scalability characteristics that are equivalent or better than the existing physical PC-based computing infrastructure.

The VDI performance, density and cost challenges are compounded when organizations deploy VDI in combination with Microsoft Windows 7 and anti-virus. Anti-virus has a significant impact on desktop performance (150ms response time increase on performance benchmarks), density of desktops per server (30percent lower density due to increased CPU and IO) and storage requirements (increase IOPS requiring additional storage disks) in a VDI environment. However, VDI benchmarking typically does not included Anti-virus in the desktop image. In order to provide customers with real-world VDI deployment benchmark and reference architecture, ALL of the published testing within this document was performed with Microsoft Windows 7 and McAfee Enterprise anti-virus.

Cisco and Atlantis Computing™ have partnered to deliver a VDI solution and reference architecture that eliminates the VDI memory and storage bottlenecks, enabling customers to deploy VDI with better performance and at a lower cost than a physical PC. The joint solution includes the following components (Figure 1).

Figure 1. Solution Components

Cisco Unified Computing System: Computing Platform

The Cisco Unified Computing System (UCS) server portfolio consists of the Blade Server platform, B-Series and the C-Series Rack Mount platform. We chose the Cisco UCS B-Series Blade Server platform running VMware vSphere 4.0 for this study. The system integrates a low-latency; lossless 10 Gigabit Ethernet unified network fabric with enterprise-class, x86-architecture servers. The system is an integrated, scalable, multi-chassis platform in which all resources participate in a unified management domain.

VDI Solution: Citrix XenDesktop

Citrix XenDesktop is a desktop virtualization solution that delivers Windows desktops as an on-demand service to any user, anywhere. With FlexCast™ delivery technology, XenDesktop can quickly and securely deliver individual applications or complete desktops to the entire enterprise, whether they are task workers, knowledge workers or mobile workers. All Citrix infrastructure components are virtualized on separate Cisco UCS blades on VMware vSphere.

VDI Storage and Performance Optimization: Atlantis ILIO™

Atlantis ILIO is a VDI storage and performance optimization solution that integrates with VDI offerings to cut storage costs, provide IT teams with more storage options and boost desktop performance. Atlantis ILIO is a unique and innovative IO virtualization technology that fundamentally changes the economics and performance characteristics of VDI by intelligently optimizing how the Microsoft Windows operating system interacts with VDI storage.

There are two Atlantis deployment options documented in the reference architecture:

Atlantis ILIO Top-of-Rack—Atlantis ILIO running one dedicated Cisco UCS B250 M2 Blade Server optimizing storage and performance for up to 8 blade servers.

Atlantis ILIO OnBlade—Atlantis ILIO running each Cisco UCS B250 M2 Blade Server optimizing storage and performance for the desktops on that blade.

The test results show that the Cisco and Atlantis VDI Reference Architecture are able to deliver the required performance, cost and scalability required by enterprise customers with Microsoft Windows 7 running anti-virus as shown in Table 1.

Table 1. Test Results

The Cisco UCS and Atlantis ILIO VDI reference architecture unites the compute, network, virtualization, storage optimization components of a VDI deployment into a cohesive and modular system designed to reduce total cost of ownership (TCO), deliver sustained desktop performance comparable to a physical PC and scale to an unlimited number of desktops without requiring large investment in additional network or storage infrastructure.