Citrix recently released a white paper detailing findings of scaling XenDesktop to 5000 virtual desktops. What is interesting about this whitepaper is not only the results, but the methodology used. Citrix opted to use VMware ESX as the hypervisor in this testing. Also, NetApp was used for shared storage. Login VSI (Virtual Session Indexer) was used to simulate workloads. Testing was done in two phases - individual component scalability and full-system scalability. Central to both phases of testing is the use of a tool that simulates real-world workloads, as well as an internally built tool to measure session startup times (providing expected user logon times). This white paper is an interesting read for both small and large VDI deployments.