Horst D. Simon and John Shalf Mail Stop 50B 4230 Lawrence Berkeley National Laboratory Berkeley, CA 94720 (510) 486-7377 (510) 496-4100 (fax) hdsimon@lbl.gov JShalf@lbl.gov Parallelism and Power in the Age of Petascale Computing We are about to enter the age of Petascale computing, By about 2009 the first Petaflop/s system will have entered the TOP500, and in the following decade we will see Petaflops computing to become more common place. Just like today Terascale computing on commodity clusters is widespread, we will see about ten tears now wide spread adoption of Petascale computers using commodity technology. By June 2016 one Petaflop/s performance will be required to enter the TOP500 list, and the age of Exaflops computing will be upon us soon after. In this talk we will survey two interrelated challenges for the age of commodity Petaflops computing: dealing with increasing parallelism and reducing the power consumption of future systems. We first point out that these challenges are interrelated, and that one way to lower power consumption is by increasing parallelism. We will also explain the seeming contradiction that low power solutions are not necessarily the most energy efficient solutions. We then claim that contrary to current hype about multicore processors that we will be able to deal with the parallelism challenge based on the experience of the HPC community in the last 15 years. Finally we will show that the problem of power consumption should be approached with a multi tier strategy, attacking the problem at the component, system, computer room, and building-environment level. We have started such a multi-tier strategy in Berkeley, and will show some early results.