Ease of programming, or programmability, is a necessary condition for
the success of any many-core platform, and teachability is a necessary
condition for programmability and in
turn for productivity. The teachability
of the XMT approach has been demonstrated extensively; for example, since
2007 more than 100 students in grades
K– 12 have learned to program XMT,
including in two magnet programs:
Montgomery Blair High School, Silver
Spring, MD, and Thomas Jefferson
High School for Science and Technology, Alexandria, VA. 22 Others are Baltimore Polytechnic High School, where
70% of the students are African American, and a summer workshop for mid-dle-school students from underrepresented groups in Montgomery County,
MD, public schools.
In the fall of 2010, I jointly conducted another experiment, this one
via video teleconferencing with Professor David Padua of the University
of Illinois, Urbana-Champaign using
Open MP and XMTC, with XMTC programming assignments run on the
XMT 64-processor FPGA machine.
Our hope was to produce a meaningful comparison of programming development time from the 30 participating Illinois students. The topics
and problems covered in the PRAM/
XMT part of the course were significantly more advanced than Open MP
alone. Having sought to demonstrate
the importance of teachability from
middle school on up, I strongly recommend that it becomes a standard
benchmark for evaluating many-core
Blake et al. 4 reported that after ana-
lyzing current desktop/laptop appli-
cations for which the goal was better
performance, the applications tend to
comprise many threads, though few
of them are used concurrently; conse-
quently, the applications fail to trans-
late the increasing thread-level paral-
lelism in hardware to performance
gains. This problem is not surprising
given that most programmers can’t
handle multi-core microprocessors.
In contrast, guided by the simple ICE
abstraction and by the rich PRAM
knowledgebase to find parallelism,
XMT programmers are able to repre-
sent that parallelism using a type of
threading the XMT hardware is engi-
neered to exploit for performance.
This work is supported by the National Science Foundation under grant
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Uzi Vishkin ( email@example.com) is a professor in the
University of Maryland Institute for Advanced Computer
Studies ( http://www.umiacs.umd.edu/~vishkin) and
Electrical and Computer Engineering Department, College