When It Comes to Data Center Management, Don't Forget Utilization

Guest Blog Post from Michael Rowan, co-founder and CTO of Viridity Software

At Viridity Software, utilization has become a rallying cry of sorts. We talk with many data center managers who need to improve their energy resource management strategies. They talk about PUE ratios and cooling costs, about server efficiency and virtualization, about high-efficiency transformers and PDUs.

We talk about utilization.

Here’s why. Most of a typical data center’s budget is spent on servers— powering them and cooling them. That EPA report that everyone likes to reference broke down the numbers. When you look specifically at the distribution of power—which, incidentally, takes up to 50 percent of data center operating expenses—servers (powering and cooling) account for 80 percent of the total balance. Another 10 percent goes to storage, and 10 percent to networking and other equipment. Cooling costs are factored in here. About half of power expenses go into cooling down what the IT equipment heated up. The bottom line is that, today, most of the power budget is really all about powering servers.

That being said, servers have evolved into much more flexible, efficient machines than they were just a few years ago. (Yes, they’re more efficient and still incredible energy hogs. Both. Maybe that’s a conversation for another day.) Current server technology has borrowed advancements from mobile devices. And why not? The developers of laptops have been so innovative in terms of extending their battery capacity—not to mention their sleek look. Now computer chips are smart and dynamic about power utilization. They modify their power consumption depending on their job.

Essentially, these computers know how to kick themselves into low gear power-wise when they aren’t doing much work. Then they crank up on power consumption commensurate with the amount of work they do. This is good news, but don’t underestimate what it means for energy management. These servers can suddenly double or even triple their power draw depending on utilization. If you’re spending almost 80 percent of your energy dollars—almost half of your entire operating budget—providing power to servers that fluctuate so dramatically, you have to monitor utilization. No other indicator impacts energy management so directly. Not by a long shot.

Put another way, if such a huge chunk of your energy budget goes into powering machines that vary their consumption rate by as much as 200 percent depending on use, can you afford to underestimate the correlation between power and utilization?

There it is, utilization. If you don’t understand utilization and its relationship to power, you don’t understand power.

-- Michael Rowan, Viridity Software Co-founder and CTO