Abstract
In a few short years, computers capable of over one Petaflops performance will become a reality. The most likely approach for first successfully reaching this performance level will involve several thousands of parallel processing elements. What are the key considerations for building such systems? What are the software requirements and demands? How will applications scale? How reliable are they likely to be? What will they be good for? We will address these questions and more based on early experience with the BlueGene system.