Servers get most of the glory when it comes to energy management, but networking gear is about to catch up.
Over the past year, network equipment vendors have began to emphasize energy-efficiency features, something that was never a top priority before, says Dale Cosgro, a product manager in Hewlett-Packard Co.'s ProCurve network products organization.
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Networking infrastructure isn't in the same class as servers or storage in terms of overall power consumption -- there are far more servers than switches -- but networking can account for up to 15 percent of the total power budget. And unlike servers, which have sophisticated power management controls, networking equipment must always be on and ready to accept traffic.
Data center energy stats
How much power does data center gear consume?
- Cisco Catalyst 6500 series switch, fully populated: 2kW/rack to 3kW/rack
- Cisco Nexus 7000 series switch, fully configured: 13kW/rack
- Fully loaded rack of servers, average load: 4kW/rack
Sources: Cisco, HP Critical Facilities Services
Also, networking power use at the rack level is significant. A Cisco Catalyst 6500 series switch consumes as much as 2kW to 3kW per 42u-high rack. Cisco Systems' largest enterprise-class switches, the Nexus 7000 series, can consume as much as 13kW per rack, according to Rob Aldrich, an architect in Cisco's advanced services group. A 13kW cabinet generates more heat than many server racks -- enough that it requires careful attention to cooling.
By way of comparison, most data centers top out at between 8kW and 10kW for server racks, says Rakesh Kumar, analyst at Gartner Inc. The average cabinet today consumes about 4kW, says Peter Gross, vice president and general manager of HP Critical Facilities Services.
Vendors have already adopted some energy-related features, such as high-efficiency power supplies and variable-speed cooling fans. But with switches, there's a limit to what can be done in the area of power management today. Most idle switches still consume 40 to 60 percent of maximum operating power. Anything less than 40 percent compromises performance, says Aldrich. "Unless users want to accept latency, you have to have the power," he adds.
But huge improvements are coming, says Cosgro.
More efficient technology
Technology improvements that favor energy efficiency are gradually evolving in several areas. "As new generations of products hit the market, more of these kinds of features will be implemented," says Cosgro. Some examples: