Less is more
Yet another strategy for optimizing server-hardware efficiency is to have power and cooling components perform double (or more) duty. For example, among HP's announcements this week was the unveiling of its HP ProLiant DL1000 Multi-Node series, which includes the DL4x170h G6, offering four server nodes in a single chassis. This approach allows the various server nodes to share power and cooling infrastructure, thus delivering an 80 percent reduction in thermal components and halving the number of power supplies. Not only is this an energy saver, it means fewer materials are necessary for the unit as a whole -- an environmental benefit.
SGI (formerly Rackable Systems) took a similar shared-component approach earlier this year with the release of its CloudRack C2, a unified server cabinet built for cluster computing applications. Each tray of the CloudRack C2 is effectively an ultra-dense 1U server, complete with standard components such as processor, board, and storage drives. However, none of these trays have power supplies or fans. Rather, the CloudRack cabinet takes care of cooling and power distribution for the trays. Again, fewer moving parts means lower overall energy consumption and fewer materials.
Growing with your needs
Yet another trait emerging among the current generation of green servers: modularity. For example, part of HP's ProLiant announcement covered the ProLiant ML330 G6, a modular tower server based on Intel Xeon 5500 processors and DDR3 memory. The ML330 is built such that IT admins can add processing power and memory capacity on an as-needed basis. Rather than having to continually replace servers as your needs grow -- which is wasteful, costly, and time-consuming -- companies can simply swap out components.
Again, though, HP isn't the only vendor to offer this sort of modularity. Dell's aforementioned PowerEdge M-series blade systems, for example, come with FlexIO switch technology for easily upgrading the machine's network connectivity up to 10Gig without replacing the base switch.
I've admittedly just skimmed the surface of the types of innovations that server vendors are devising to make their wares greener. Other techniques include developing smarter management software for measuring and managing power consumption (offered by HP and IBM, for example), and building boxes that support more virtual machines.
And let's not forget there are ways for customers to wring even more energy efficiency from their servers, such as exposing their servers to significantly higher temperatures; removing superfluous components from their machines, à la Google; or powering down servers when they aren't in use. Granted, such techniques aren't traditional (yet) and thus might not be attempted at more risk-averse IT departments. Fortunately, server vendors are making green features standard on their wares, which means you can still enjoy power savings the moment you plug in the machine.