Sun Formally Acknowledges the Research
Contribution of Z. Zhang, Z. Zhu, and X. Zhang to the Memory System
Design in UltraSPARC IIIi Processor
A permutation-based memory interleaving technique, called "XOR
interleaving" or "permutation interleaving" proposed by Zhao Zhang
(Ph.D.'02), Zhichun Zhu (Ph.D.'03), and Xiaodong Zhang has been
adopted in the Sun MicroSystems' UltraSPARC IIIi processor. A paper
about this technique entitled "A permutation-based page interleaving
scheme to reduce row-buffer conflicts and exploit data locality" was
presented and published in the 33rd Annual IEEE/ACM International
Symposium on Microarchitecture (Micro-33, pp. 32-41, Monterey,
California, December 10-13, 2000). Having conducted intensive
experiments and thorough analyses, the three W&M researchers
showed that address mapping conflicts at the cache level, including
address conflicts and write-back conflicts, will inevitably
propagate to the memory address space under a standard memory
interleaving method, causing a significant memory access delay. This
important finding was first published in this Micro-33 paper, and
their proposed permutation interleaving technique effectively solves
the conflict problem with a trivial hardware cost. In addition to
supporting the XOR interleaving technique in UltraSPARC IIIi
processors, the finding of memory address conflict propagations in
the Micro-33 paper has also been quoted in Technical Manuals of
UltraSPARC IIIi processor related systems by the Sun MicroSystems.
In July 2005, the Sun MicroSystems Inc. sent a formal
acknowledgement letter to the College of William and Mary to
recognize the research contribution of Z. Zhang, Z. Zhu, and X.
Zhang. The UltraSPARC IIIi processors are used in in both entry
level servers, such as Sun Fire V210, V240, V250, and V440 servers,
and in workstation and desktop products, such as Sun Blade 1500
workstations.
Xiaodong Zhang, Lettie Pate Evans Professor of Computer Science
and the Department Chair, says, "I and my former students Zhao Zhang
(an assistant professor of electrical and computer engineering at
the Iowa State University) and Zhichun Zhu (an assistant professor
of electrical and computer engineering at the University of Illinois
at Chicago) feel very rewarding to see the strong impact of our
research work to the computer industry and to our daily computing
operations".
The Department of Computer Science The College of William &
Mary McGlothlin-Street Hall, Room 126
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