The Power 775 Architecture at Scale

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 FFT 1. 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. For the scale of the systems we have achieved, such bandwidth is unprecedented. 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

By: R. Rajamony, M. W. Stephenson, W. E. Speight

Published in: RC25366 in 2013


This Research Report is available. This report has been submitted for publication outside of IBM and will probably be copyrighted if accepted for publication. It has been issued as a Research Report for early dissemination of its contents. In view of the transfer of copyright to the outside publisher, its distribution outside of IBM prior to publication should be limited to peer communications and specific requests. After outside publication, requests should be filled only by reprints or legally obtained copies of the article (e.g., payment of royalties). I have read and understand this notice and am a member of the scientific community outside or inside of IBM seeking a single copy only.


Questions about this service can be mailed to .