Microsoft's Low-Power Server Prototype

How low can your server power go? Microsoft is investigating that question in a project by its new Cloud Computing Futures (CCF) research unit, which aims to reduce data center costs by "four-fold or greater." The new group was introduced today at the Microsoft TechFest in Redmond. One of CCF's initial research projects is testing the viability of a small cloud computing server farm using low-power Intel Atom processors originally designed for use in netbooks and mobile applications.

"In addition to requiring far less energy - 5 watts versus 50 to 100 watts for a processor typically used in a data center- low-power processors also have quiescent states that consume little energy and can be awakened quickly," explained Dan Reed, director of Scalable and Multicore Systems for Cloud Computing Futures. "These states are used in the sleep and hibernate features of laptops and netbooks. With our current Atom processor, its energy consumption when running is 28 to 34 watts, but in the sleep or hibernate state, it consumes 3 to 4 watts, a reduction of 10 times in the energy consumption of idle processors."

In this brief video, CCF Director of Software Architecture Jim Larus demonstrates a prototype rack packed with these low-power processors:

That wasn't the only data center project discussed at TechFest.
The Cloud Computing Futures team also discussed Marlowe, a system for selectively putting idle servers into a low-power state. Reed said Marlowe "highlights the power of an intelligent control system that can determine when to put a processor to sleep and when to awaken it to service the workload.

"This problem has two interesting challenges," he said. "The first is to estimate how many processors are necessary to handle a given workload by responding to every request in a timely manner. (By analogy, how many checkout clerks should be at the cash registers?) The second is to anticipate the workload in the near future, since it takes 5 to 15 seconds to awaken a processor from sleep and 30 to 45 seconds for hibernate. The system needs to hold some processors in reserve and to anticipate the workload 5 to 45 seconds in the future to ensure that sufficient servers are available."

The solution was a closed-loop control system. "It works by taking regular measurements of the system, such as CPU utilization, response time, and energy consumption; combining this data with the estimated future workload; then adjusting the number of servers in each power state," Reed said.

Microsoft Research has published "posters" that provide an overview of both Marlowe and the low-powered server projects. You can also read an extended interview with Reed about Microsoft's plans for Cloud Computing Futures.