文档介绍：PERFORMANCE ANAL'VSIS FORMULAS
Amdahl's Law
Let f be the fraction of operations in putation that must be performed
sequentially, where 0 f < I. The maximum speedup l{! achievable by aparallel
computer with p processors performing putation is Parallel Programming
in C with MPI
"'::;f+O­
andOpenMP
Gustafson-Barsis's Law
Given a parallel program solving a problem of size Il using p processors, let s
denote the fraction of total execution time spent in serial code. The maximum Michael J. Quinn
speedup 1/J achievable by this program is State n.'. ____ ..'L
l{!'::;/J+(l-p)s
Karp-Flatt Metric
C,IUUlllllll/,; speedup if! on pprocessors, where p > I,
the experimentally determined serial fraction e is defined to be
e --IN-lip.....­
I-lip
Isoefficiency Relation
a parallel system exhibits efficiency
size and p denotes number of processors. Define C = f(n, p)/O
T(n, I) denote sequential execution lime, and let 7;,(11, p) denote parallel over­
head (total amount of time spent by all processors munications
and putations). In order to maintain the same level of efficiency as
the number of processors increases, problem size must be increased so that the
fa \lowing inequality is satisfied: IIHigher Education"
)~ p)
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The McGr(lwHifI (Ompunie$f';~~"
W'dh gratitude for their love, support, and guidance,
I dedicate this book to mv parents,
II
Edward and ia Quinn.
PARALLEL PROGRAMMING IN C WITH MP! AND OPENMP
International Edition 2003
Exclusive rights by McGraw,HiII Education (Asia), for manufacture and export. This
book cannot be re-exported from the country to which it is sold by McGraw-HlU. The
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