Of all the issues facing today's data center manager, heat/power distribution top the list. Available uptime and growth constraints round out the top three.
And it doesn't appear this will change any time soon. With the high cost of data center floor space climbing more and more every day, data center managers are trying to squeeze every last square foot out of their cabinets. They're utilizing high density applications like cluster server configurations and blade servers, thereby increasing processor power per equipment footprint and increasing the amount of power required at the cabinet level.
It is now estimated that after just three years on the market, blade servers account for seven percent of all server shipments sold; with estimates showing that by 2008 they will make up thirty percent of all servers sold. It is expected that they will be the fastest growing server form factor through 2009.
So, how do you power a cabinet where the power requirements could exceed 40 kiloWatts?
There are many different circuit combinations that can be used to provide power to today’s densely populated cabinets. Many servers today are designed to take a large range of input voltage from 120V to 208V. Typically smaller servers that may or may not be rack mountable require 120 V. Most of today’s larger high density servers, such as blade servers require 208V power. While the floor space required to achieve a constant level of computing and storage capacity has shrunk, the energy efficiency of the equipment has not increased at the same rate. As a result, the power consumed and the heat dissipated has increased significantly within the cabinet foot print.
With increased power consumption comes important decisions that must be made with regards to cabinet level power requirements and selecting the proper CDU (Cabinet Distribution Unit). Tough choices like what power is brought down to the cabinet level such as 120V 15 or 20A, 208V 20 or 30A, 208V 30A 3-Phase or even 208V 60A 3-Phase are important decisions that effect costs, performance and the ability to provide for future expansion. The number of power drops that must be run to each cabinet greatly affects the cost and whether or not there is sufficient power available for current needs and expansion. This is especially true in critical applications where redundant power is necessary. Each power drop run to a cabinet costs $500 to $1,500 or more; as well as having other consequences such as the number of CDU’s required or whether or not cable management is a problem. This cost varies depending on several factors including panel space, distance, and what area the receptacles will be located in.
Only time will tell if future capacity demands will continue to increase power consumption and cooling levels to higher and higher levels. Current ASHRAE projections certainly predict that they will. Other technologies such as virtualization, dual core processors, and new more efficient processor designs along with current and future software solutions will ultimately determine the outcome.
Read more about High Density Solutions in Server Technology's Blade Server Power Solutions Whitepaper.