Saving Power Can Cause Problems for Your Data Center

By Michael
February 9, 2010

Light_bulb_energyToday’s computer processors are designed to save power. But that wasn’t always the case.

Technology once reserved for conserving juice on notebook computers has been incorporated into desktop computers and servers. While generally this has been a good development, it can create problems in the data center, as APC Consulting Engineer Jim Spitaels pointed out recently in a white paper entitled Dyanamic Power Variations in Data Centers and Network Rooms.

Until the arrival of processors that managed their power draw based on computational demand, the processing load on the data center had little impact on its power consumption. Regardless of the load placed on the center, power consumption varied in the area of five percent. With the new processors, though, power demands can fluctuate significantly. The amount of power a processor uses when a light computational load is placed on its resources compared to what it draws when it’s tackling a heavy load can vary from 45 to 105 percent. That can create real problems for a data center administrator.

Increased power demands due to a jump in the computational load on a system can create power surges that trip circuit breakers and shut down a data center at inconvenient times, most likely when large numbers of transactions need to be processed.

Load demands on hardware at specific locations within the data center can create hotspots that cooling systems can’t handle. The result can be server shutdowns caused by overheating.

Redundant systems may fail, too. A data center’s power architecture usually has dual power paths. When one fails, the other picks up the slack. However, each path  must carry less than 50 percent of the total capacity for the two paths. Due to a dynamic load change, one path may exceed 50 percent and not be able to cover the load when the other path fails.

As Spitaels writes: 

“The percentage of Information Technology loads in the network room or data center, which exhibit a power consumption that varies significantly with load, is increasing over time. This situation gives rise to a number of unanticipated problems for operators of data center infrastructure.

The procedures historically used to minimize the risk of overload must adapt to this new reality. Proper planning and branch circuit power monitoring are critical for ensuring availability in both new and existing facilities where large numbers of servers will be installed.”

So although power-saving technology may be driving down costs in your data center, it doesn’t come without challenges, which if not handled properly, can cost you more than savings reaped from more efficient technology.

Leave A Comment