Another worthwhile list to look at is the Green500 [1], which ranks machines based on MFLOPS/Watt. With the exception of a few GPU and Xeon Phi heavy machines

Another worthwhile list to look at is the Green500 [1], which ranks machines based on MFLOPS/Watt. With the exception of a few GPU and Xeon Phi heavy machines at the top, the high end is dominated by IBM's Blue Gene machines. [1] http://www.green500.org/lists/green201306&green500from=1&green500to=100 http://www.green500.org/lists/green201306&green500from=1&gre...