Just posted this blog entry with Adam Bogobowicz.

Little and Large

When you hear the phrase “green IT”, you know that the word virtualization will usually appear shortly afterwards. Virtualization provides the ability to consolidate your IT infrastructure from several physical computers (each of which has a basic power overhead) onto virtual computers running on significantly fewer host computers. The increase in power consumption for each virtual computer you run on the host is considerably less than the power overhead for each replaced physical computer.

At this point, you can usually hear the sounds of hardware manufacturers rubbing their hands with glee. This enthusiasm results from the prevalent association that virtualization (and especially consolidation) requires multi-core processing capacity with associated power consumption rates. A good example of this type of hardware would be the recently announced Nehalem-EX processor from Intel. Everything is larger and more numerous on this chip when compared to the previous generation:

8 cores

9 times the memory bandwidth

16 simultaneous threads

24MB of cache

2,300,000,000 transistors

If consolidation is the route you want to take and you have multiple physical computers to consolidate, then this processor would certainly be a good choice. But what if you see virtualization as an aid to manageability rather than consolidation and you want to conserve power?

O Fortuna

At the opposite end of the spectrum from Nehalem-EX systems is the diminutive Dell XS11-VX8, better known by its codename of “Fortuna.” If you are having trouble with the scale of this devices, that silvery part with the white label on the back of the server is the 3.5” hard disk. Yet this pocket-sized computer is no toy, but a true, enterprise-ready, 64-bit, hardware virtualization enabled, self-contained server with dual NICs and 2GB RAM that supports IPMI and iSCSI. The processor is the Via Nano, one of the most economical processors on the market with full hardware virtualization support for Hyper-V.

The post is a bit longer at http://blogs.msdn.com/the_power_of_software/archive/2009/06/08/little-and-large.aspx