We describe the IBM Power 775, a supercomputing system that was designed to provide high performance at very large scales. The system recently attained world record performance numbers for three important, communication-heavy supercomputing benchmarks: RandomAccess, PTRANS, and Global FFT. At the heart of the Power 775's performance is the "hub module", which is a high-radix router containing forty-seven copper and optical links with a switching capacity of over 1.1 Tbyte/second. This level of bandwidth is unprecedented for typical systems of the scale we discuss in this paper. As a result, we were forced to develop a complete software stack to fully leverage the communication capabilities of the system. In this paper we evaluate the Power 775 server at scales up to 2 Petaflops (63,360 POWER7 cores), discuss hardware and software tradeoffs considered during the design process, and finally present some lessons learned.

No abstract

No abstract

No abstract