Power requirements for IT equipment are typically derived from peak power consumption estimates, the manufacturer ‘nameplate specs’, not actual or real world figures. While this is fine for wiring the data center, it’s very ineffective for optimizing power usage. The result is a gross over-provisioning of the data center power infrastructure and less than successful efforts at minimizing power usage. Also affected are cooling systems, which are designed to support peak power consumption levels.

Viridity’s EnergyCenter software provides real world consumption numbers for servers by model and configuration at different load levels, from a database they’ve developed through lab testing of actual servers and applications. According to CTO Mike Rowan, a server’s power usage can fluctuate 200-300% based on CPU loading. With EnergyCenter, power usage is monitored based on real time CPU utilization. This means IT managers can manage power intelligently to minimize OpEx costs. With this kind of granular data, they can also save CapEx costs by adding servers to an existing data center, instead of expanding or relocating it because the original over-provisioned estimates have been reached.

Server virtualization has only added to the misconception about power usage, according  to Rowan. “Many of the IT people we talk with say ‘we’re 60% virtualized, we’re fine on power’. But the fact is they don’t really know how much power their servers are actually using”. Viridity’s EnergyCenter can display real time data on power and CPU usage and show which servers are underutilized or inefficient and therefor, good candidates for virtualization. This data can also help with server placement in the data center for load balancing and efficient cooling.

Rowan said, “If all you can see is how much power a rack consumes, all you can do is unplug the rack. When a company’s power bill is close to their CapEx budget (not uncommon) they’re real interested in optimizing their power infrastructure. But they need better tools to get this done.”