This is a long shot because I *think* this is a new(ish) approach, but has anyone calculated the DMTF's proposed Data Center Productivity (DCeP) for VDI?

http://www.thegreengrid.org/en/Global/Content/white-papers/Proxy-Proposals-for-Measuring-Data-Center-Efficiency

The jist is to calculate Useful Work per IT Watts In. Amazon Web Services have something similar they call "work per joule".

In VDI's case, if we say equate Useful Work with Virtual Desktops of the same Unit of Compute (e.g. 512MHz / 512 MB), and it takes 50kW/h to power our solution (including all compute, LAN access layer, load balancers, client device managers and connection brokers + any dedicated SAN fabric + array), then perhaps we can work out two interesting numbers that we can use to compare the efficiency of one solution to another?

If anyone has done this, I'd love to hear from you. If anyone is interested in combining brain cells to work something out, I'd love to hear from you. If you think I'm mental, keep it to yourself!

:-)

Steve