You’ve seen the demo and have downloaded the VDI-in-a-Box trial software. Your PC/VDI-in-a-Box side by side user tests are going great; the price is well within your budget; and you have seen it’s going to be a dream to support. So now you need to figure out what servers you need to use in production.

You have several server choices: Dell’s DVS Simplified 1010 VDI appliance (PowerEdge 710 with XenServer hypervisor and VDI-in-a-Box pre-installed), HP’s reference architecture (for their ProLiant DL380p Gen8), or you can size and select your own.

Citrix provides a Server Sizing Guide to help you figure out what components and performance your server(s) need for the amount of desktops you plan to deploy. The Guide covers the requirements for CPU, memory, number of disks and storage.

Although the Guide is easy to understand and the formulas are simple, it sure would be nice to have an automated way to do this. Enter some basic info – like number of concurrent users and images, and all the required items would be listed out for you. It would also be nice to have the ability to select various options to see how they affect the overall server configuration. Things like Raid configurations, disk speed, hyper-threading CPUs and high-availability.

Well, such a tool now exists for our partners, customers and prospects. Partners can find the tool on www.citrix.com/skb. Just select VDI-in-a-Box and download the Server Sizing Calculator. Customers/prospects can find the tool on www.citrix.com under the VDI-in-a-Box Resources and Support page.

It’s a simple Excel spreadsheet, fully documented with notes and a page of all the formulas (in English, not code). It suggests the number of servers, server components, options and sizing required to support the specified number of desktops you wish to deploy.  Keep in mind, the configuration provided should be used as a starting point for sizing your server, as the performance of the desktops will depend on many factors including the user workload, the applications, the hypervisor, and the type of server components (e.g. type of CPU and its clock speed, amount of L1/L2 cache, cache size of disk controllers, and so on).  The tool will configure a server to handle up to 100 desktops.  Above that it will calculate the desktops over multiple, identically configured servers (e.g. for a 250 concurrent user requirement, the tool will size a server for up to 84 desktops, of which you would need 3).

Check it out and let us know what you think.