Overview of the QCDSP and QCDOC computers

• Published in: IBM journal of research and development Vol. 49; no. 2-3; pp. 351 - 365
• Main Authors: Boyle, P A, Chen, D, Christ, N H, Clark, M A
• Format: Journal Article
• Language: English
• Published: Armonk International Business Machines Corporation 01.03.2005
• Subjects: Communication; Computer architecture; Computer networks; Computers; Design; Digital signal processors; Electromagnetism; Quarks; Software; Spacetime
• ISSN: 0018-8646; 0018-8646; 2151-8556
• DOI: 10.1147/rd.492.0351

The QCDSP and QCDOC computers are two generations of multithousand-node multidimensional mesh-based computers designed to study quantum chromodynamics (QCD), the theory of the strong nuclear force. QCDSP (QCD on digital signal processors), a four-dimensional mesh machine, was completed in 1998; in that year, it won the Gordon Bell Prize in the price/performance category. Two large installations-of 8,192 and 12,288 nodes, with a combined peak speed of one teraflops-have been in operation since. QCD-on-a-chip (QCDOC) utilizes a six-dimensional mesh and compute nodes fabricated with IBM system-on-a-chip technology. It offers a tenfold improvement in price/ performance. Currently, 100-node versions are operating, and there are plans to build three 12,288-node, 10-teraflops machines. In this paper, we describe the architecture of both the QCDSP and QCDOC machines, the operating systems employed, the user software environment, and the performance of our application-lattice QCD. [PUBLICATION ABSTRACT]