Power7 Hub Chip Key to IBM’s PERCS Super
At the Hot Chips 22 conference this week at Stanford University, IBM engineers shed some light on the interconnect hub chip that is connecting the Power7 nodes on their PERCS supercomputing system. PERCS ((Productive, Easy-to-use, Reliable Computing System) is IBM’s contribution to DARPA’s High Productivity Computing Systems (HPCS) program, whose goal is to deliver highly productive multi-petaflop supercomputing systems for government and industry.
Although both IBM’s and Cray’s HPCS designs rely on general-purpose processors — Power7, in the case of IBM, and Opteron, in the case of Cray — the hub controllers are proprietary devices that turn these machines in elite supercomputers. Likewise, SGI’s Altix UV hub is the secret sauce that makes the shared memory capability on the company’s new UV machines possible.
The PERCS IBM hub module contains 48 10Gbps optical links and delivers more than 1.1 terabytes/second of bandwidth. A hub connects each Power7 quad-chip module (QCM), with each Power7 drawer consisting of 8 QCMs and 8 hubs. Presumably this is the same setup going into the PERCS-class Blue Waters system at NCSA.
Rick Merritt covered the IBM presentation at Hot Chips 22 for EE Times, and has a nice writeup, along with a video interview of Baba Arimilli, the chief architect of the hub chip.
Full story at EE Times