Disk allocation: Many of the default values in calculators assume 10 GB of space. In 2009, Gartner concluded that 25 GB is the actual midpoint for most users.1 But with the proliferation of video, music, and graphic elements in even fairly basic work products, many users are now filling up drives of 100 GB or more and even adding 500 GB USB drives for extra storage. Organizations need to truly analyze and understand the data storage needs of their users before arriving at a conclusion. Different user types may need very different data allocations. Software Software licensing costs are often considered in TCO and ROI calculation tools as a potential source of savings. Organizations should be cautious about assuming these savings without a clear understanding of software license agreements. In addition to new software required to run the central servers, most desktop applications charge on a per-user basis and do not allow concurrent user licensing. The end result is often an increase in overall software and software support costs, not a decrease. Many organizations have seen an initial software cost reduction only to discover during software audits that are they are in violation of their software agreements, and they end up paying both the full license costs as well as applicable fines. Organizations that virtualize their designers, developers, or other specialty roles often find that these users require an intelligent desktop due to the nonstandard applications they need to run. As a result, two standard licenses are required for each of these users, one for each machine.
Energy Energy matters not only because of how energy costs affect the bottom line, but also because organizations often investigate virtualization in part because they want to create a sustainable or “green” environment for employees and demonstrate corporate responsibility to customers and shareholders. Assuming thin devices are used to access vertical desktops (versus using an older intelligent PC as a dumb terminal), there can be energy savings at the user point. However, these savings may be balanced by user behavior (do they turn off their computer at night, and are power settings configured to optimize energy consumption?) and the energy burden of running and cooling the new servers. Depending on the organization’s current data center, implementing virtualized desktops may require data center and cooling system upgrades. Data Center Real Estate Similar to energy, real estate considerations should not be underestimated when evaluating the TCO of desktop virtualization. Replacing a traditional intelligent client desktop device with a new thin device is unlikely to reduce the real estate requirements of each employee. However, the addition of many new servers will definitely increase the amount of real estate required in the data center. There are possible trade-offs related to data center real estate versus cooling (for example, the denser the servers are racked, the less impact on real estate but the greater the need for cooling), but in general, moving to a virtualized desktop will add additional real estate, security, and other facility-related costs such as maintenance and janitorial costs.
Support One potential benefit of virtualization is reducing desktop support costs. Because servers can be maintained and controlled in a more effective manner than most traditional intelligent desktop environments, the need for desk-side support should lessen. However, three important elements should be considered when calculating true support savings. Reduced user-side support: It is more cost-effective to support users remotely than to provide desk-side assistance. While these benefits are normally realized as part of desktop virtualization, organizations can potentially realize similar savings by employing low-cost remote desktop applications that allow support personnel to remotely take control of the end user’s local machine to resolve support issues. Increased cost of support personnel: The skill set needed to support and maintain virtual desktops is often greater than for supporting and maintaining traditional desktops. Although the total number of support full-time employees (FTEs) may reduce, the average cost per FTE may increase.
1 Dayley, Alan. User Survey Analysis: Virtualization Cost Reduction and Consolidation Promises Slow in Coming. Gartner, 2009
14 Intel IT Center Planning Guide | Desktop Virtualization