Basic HTML version of Foils prepared August 7 98

Foil 24 Conjugate Gradient: Agglomeration

From DoD HPF Training -- 5. Parallel Programming in HPF DoD Training and Others -- 1995-98. by Chuck Koelbel -- Rice University
Dot products and convergence test always require global communication
  • No reason to pick one DISTRIBUTE over another
Vector updates require no communication
  • Really no reason to choose a particular DISTRIBUTE
Matrix-vector multiply does care where its data come from
  • In this case, same advantages/disadvantages as Jacobi iteration
The bottom line
  • (BLOCK,*) on high-latency machines or small problem sizes
  • (BLOCK,BLOCK) on low-latency machines

© Northeast Parallel Architectures Center, Syracuse University, npac@npac.syr.edu

If you have any comments about this server, send e-mail to webmaster@npac.syr.edu.

Page produced by wwwfoil on Sun Aug 16 1998