BALTIMORE–IBM is working to deliver technology that could lead to zero-emission data centers, said an IBM researcher at a USENIX conference here Nov. 6.
At the USENIX Large Installation System Administration conference, Bruno Michel, manager of Advanced Thermal Packaging at IBM’s Zurich Research Laboratory, said his team is working on new ways to reduce emissions and waste in data centers, including methods such as chip stacking and liquid cooling.
Michel said, “High-performance liquid cooling allows data centers to operate with coolant temperatures above the free cooling limit in all climates, eliminating the need for chillers and allowing the thermal energy to be reused in cold climates,” such as that in Zurich. Indeed, at IBM’s Zurich lab, Michel’s team has “demonstrated the removal of 85 percent of the heat load from high-performance compute nodes at a temperature of 60 degrees Celsius and compared their energy and emission balance with a classical air-cooled data center, a data center with free cooling in a cold climate zone and a data center with chiller-mediated energy reuse,” he said in the presentation’s introductory text.
“We thought that computers do a lot for biology and we wanted to see what biology can do for computers,” Michel said, noting that a well-functioning computing system in a data center can work very much like a body’s circulatory system.
Michel said data centers are consuming more and more energy, with data center energy consumption doubling over the last four years. “Future data centers will be dominated by energy cost, with half of that being spent on coolant,” if nothing is done, he said.
And demand for computing power will only continue to grow with drivers such as mobility and telecommunications, digital media, 24/7 e-commerce, high-performance computing, real-time systems and compliance pushing users to grasp for more and more compute cycles and greater performance.
With that in mind, IBM and the Swiss Federal Institute of Technology Zurich are working on a “first-of-a-kind water-cooled supercomputer that will directly repurpose excess heat for the university buildings, IBM said in a June 23 news release. The system is called Aquasar and is “expected to decrease the carbon footprint of the system by up to 85 percent and estimated to save up to 30 tons of CO2 per year, compared to a similar system using today’s cooling technologies.”
“We reuse waste heat for remote heating,” Michel said. “The prototype reuses 75 percent of the energy” put into it, he added.
“The vision is that within five years we can have a zero-emission data center,” he said.
Aquasar is slated for delivery by April of 2010, Michel said.
The Importance of Liquid Cooling
“Energy is arguably the No. 1 challenge humanity will be facing in the 21st century. We cannot afford anymore to design computer systems based on the criterion of computational speed and performance alone,” Prof. Dr. Dimos Poulikakos of ETH Zurich, head of the Laboratory of Thermodynamics in Emerging Technologies and lead investigator of the project, said in the June release. “The new target must be high-performance and low-net-power-consumption supercomputers and data centers. This means liquid cooling.”
Aquasar is expected to “reduce overall energy consumption by 40 percent. The system is based on long-term joint research collaboration of ETH and IBM scientists in the field of chip-level water cooling, as well as on a concept for ‘water-cooled data centers with direct energy reuse’ advanced by scientists at IBM’s Zurich Lab.
“The water-cooled supercomputer will consist of two IBM BladeCenter servers in one rack and will have a peak performance of about 10 Teraflops,” the June release said.
“We’re starting with a [IBM] Roadrunner-type machine to reach world-record performance and low emissions,” Michel said.
IBM in the June release said, “Each of the blades will be equipped with a microscale high-performance liquid cooler per processor, as well as input and output pipeline networks and connections, which allow each blade to be connected and disconnected easily to [and from] the entire system. …
“Water as a coolant has the ability to capture heat about 4,000 times more efficiently than air, and its heat-transporting properties are also far superior. Chip-level cooling with a water temperature of approximately 60 degrees C is sufficient to keep the chip at operating temperatures well below the maximally allowed 85 degrees C. The high input temperature of the coolant results in an even higher-grade heat as an output, which in this case will be about 65 degrees C.”
“Heat is a valuable commodity that we rely on and pay dearly for in our everyday lives,” Michel said. “If we capture and transport the waste heat from the active components in a computer system as efficiently as possible, we can reuse it as a resource, thus saving energy and lowering carbon emissions. This project is a significant step toward energy-aware, emission-free computing and data centers.”
Michel said even in hot climates the excess heat can be used for desalination projects and other purposes.
In the June release, IBM said, “The computational performance of Aquasar is a very important part of the research. Aquasar will be employed by the Computational Science and Engineering Lab of the Computer Science Department at ETH Zurich, for multiscale flow simulations pertaining to problems encountered at the interface of nanotechnology and fluid dynamics. Researchers from this laboratory will also optimize the efficiency with which the respective algorithms perform within the system, in collaboration with the IBM Zurich Lab. These activities will be supplemented with algorithms of other research labs participating in the project. With this supercomputer system, scientists intend to demonstrate that the ability to solve important scientific problems efficiently does not need to have an adverse effect on the energy and environmental challenges facing humanity.”