Simply scaling up today’s supercomputer architecture to build an exascale supercomputer would lead to a machine that requires the equivalent of a gigawatt-scale nuclear power plant, wrote Peter Kogge, a computer scientist and engineer at Notre Dame University, in IEEE Spectrum in January 2011. Instead, the U.S. government hopes to achieve practical exascale supercomputing in the 2020s at a cost of about US $200 million and 20 to 30 megawatts of power, says Horst Simon, deputy director at Lawrence Berkeley National Laboratory, in California. (One megawatt could cost a U.S. national lab about $1 million annually.)