Hi MATLAB community,
I know that function pcg is supported in the Parallel Computing Toolbox for use in data parallel computations with distributed arrays, i am using a HPC architecture that it's made of 8 nodes, each blade consists of 2 quadcore processors sharing memory for a total of 8 cores and of 64 cores, in total. I run pcg on 1 core and pcg with distributed arrays on 32 cores.
[x,flagCG_1,iter] = pcg(@(x)gather(A*x),b,,100);
i obtained that
Elapsed time is 0.001279 seconds. %first case
Elapsed time is 0.316632 seconds. %second case on 32 cores
why the time in second case is greater than the time in first case? what am I doing wrong ?
Thanks for your help