How Pandora, Alibris slashed their data-center power needs

It’s no secret that data centers consume large amounts of energy. Between powering and cooling all the equipment found in a data center, including servers, networking gear, and storage, a lot of electricity and money goes into maintaining our digital world. With so much budget focused on keeping datacenters running at top speed, finding a green solution is a lofty goal, particularly since few companies will go green if it means sacrificing responsiveness to customers.

The call for greening the world’s data centers is not new. In 2006, a congressional study released by the Environmental Protection Agency (EPA) showed U.S. data centers consumed an estimated 61 billion kilowatt-hours (kWh) of energy each year. This usage accounted for about 1.5 percent of the total electricity consumed in the U.S. in 2006. The report also said data centers’ cooling infrastructure accounts for about half of that electricity consumption.

While it may seem fighting data-center-energy consumption is futile, the EPA estimated that implementing cutting-edge energy-saving technology could slash energy usage by 70 percent. For many, these savings seem impossible to achieve without cannibalizing performance. But that was before flash memory was added into servers as a new memory tier sitting between fast and expensive DRAM and slow disk storage.

With more capacity than DRAM and far more speed than disk drives, NAND flash memory is rapidly becoming a staple in today’s data centers. This new technology improves application performance, while requiring far less power-hungry infrastructure -- giving companies the best of both worlds.

Powering a greener Pandora

A prime example is personalized Internet radio leader Pandora, which recently deployed flash memory in its caching servers, increasing the amount of cache each server could hold by 10 times, or 1,000 percent. This allowed Pandora to increase the number of songs it could hold in its caching tier, meaning more songs streamed at top speeds. But it also allowed the company to reduce its server footprint by 40 percent, resulting in an instant ROI on repurposed servers.

By replacing servers loaded with small amounts of DRAM with servers loaded with large capacities of low-power flash memory for caching data, Pandora lowered the power and cooling costs of its system, while reducing maintenance overhead. For companies around the world, it is inspiring to see that Pandora was able to achieve better performance and lower its hardware costs, while saving energy --all from one solution.

Flash memory is also being used to reduce the energy drain from disk-based storage systems. Flash memory is more powerful than disk drives, enabling companies to pack more performance into a smaller space. By switching to flash memory, book eRetailer Alibris was able to replace two search system racks -- filled with 34 servers and 144 hard disks -- with just two mirrored (backed up) servers, representing a 94 percent reduction in hardware. The energy savings from having fewer servers to power -- as well as from needing less cooling to keep those servers running smoothly -- is staggering, not to mention the reduction in electronic waste.