By now you've read a lot about green data centers. You've certainly heard all about IT's contribution to the growing need for power. But at the end of the day, what does it all mean? What is the reality of IT power consumption trends and how is that reality impacted by the core of the data center: the server?

I've spent most of my career asking these same questions. I drive systems-level energy strategy --- from the chip right on through the operating system layers and system software --- at Sun Microsystems. I'm helping ensure that our technologies and products are eco-responsible.

Earlier in my tenure with Sun, I was responsible for the technology direction for our blade servers, rack-mount servers, telecom-optimized servers, technical compute servers and workstations. I also drove the design and strategies for the next-generation system architectures, interconnects, and networking standards. Learning how to build efficient server architectures was great preparation for learning how to build efficient data centers.

So What's the Problem?
I think it's fair to say that we all understand the problem. The cost of power as a percentage of overall IT spending ranges from 20 percent for a small enterprise data center to about 80 percent for very large hosting and collocation providers. And if you deconstruct data center power needs further, it becomes clear that the largest resource hogs are the servers, storage and switch infrastructure---ironically, equaled by the resources required of the cooling units to keep the temperatures of these rack-mount devices in check.

Given the rising cost of electricity, it is estimated that the power and cooling costs required to run a low-cost server may outweigh the acquisition cost of that server in the very near future. That's not great news. However, I believe 2008 is a watershed year for energy-efficiency in IT. The environmental impacts of massive, global data centers make eco-responsibility more important than ever.

Light at the End of the Hot Aisle
I don't know about your environment, but many of our customers see no end to the pressures to deploy more applications and support greater numbers of users. New applications and the data resources to support them are squeezed into the existing data center footprint, compounding the problem. We're seeing a space, power and cooling crunch born out of the need for more, bigger and faster resources.

This modus operandi is further complicated by the silo approach to server resource sizing, where application server needs are sized to handle the maximum need at any given time. Extra server capacity simply sits idle, consuming resources.

But there is an end in sight. As an engineer, I'm thrilled at the progress we're making as an industry in a short amount of time.

The challenge is to build energy-efficient servers that provide superior computing power but require less energy to run --- and to manufacture, too. That goal requires a relentless focus on delivering performance per watt at every level of the stack. In the past, our industry focused on producing faster and higher-performing servers, with little regard for their power consumption. The tide is starting to change industry-wide, though, as more vendors emphasize increased energy efficiency, without sacrificing either performance or reliability.

At the Core -- Enter the Energy-Efficient Server
I believe that the solution to building more efficient data centers is two-fold: Use more powerful, eco-responsible servers, while at the same time, increase the overall efficiency of the data center by improving power distribution and cooling.

As a rule of thumb, for every watt delivered to power today's IT equipment, at least one additional watt is spent on overhead, including power and cooling resources. We can have a dramatic impact on overall power consumption by reducing the load and increasing the efficiency of power and cooling.