I think I’m missing something fundamental about using distributed arrays with spmd. If I run the following the distributed version takes ~0.04s while the non-distributed version completes in ~0.2s (with a process pool matching the cores on my machine).
x = ones(10000, 10000);
tic
x = x * 2.3;
toc
x

x = distributed(ones(10000, 10000));
tic
spmd
x = x * 2.3;
end
toc
gather(x)
What am I missing?

Edit: I moved the tic and toc to after the array initialization and before displaying x to not include that as I realized calling distributed is taking longer while it distributes the array across the processes and gather is taking time.I think I’m missing something fundamental about using distributed arrays with spmd. If I run the following the distributed version takes ~0.04s while the non-distributed version completes in ~0.2s (with a process pool matching the cores on my machine).
x = ones(10000, 10000);
tic
x = x * 2.3;
toc
x

x = distributed(ones(10000, 10000));
tic
spmd
x = x * 2.3;
end
toc
gather(x)
What am I missing?

Edit: I moved the tic and toc to after the array initialization and before displaying x to not include that as I realized calling distributed is taking longer while it distributes the array across the processes and gather is taking time. I think I’m missing something fundamental about using distributed arrays with spmd. If I run the following the distributed version takes ~0.04s while the non-distributed version completes in ~0.2s (with a process pool matching the cores on my machine).
x = ones(10000, 10000);
tic
x = x * 2.3;
toc
x

x = distributed(ones(10000, 10000));
tic
spmd
x = x * 2.3;
end
toc
gather(x)
What am I missing?

Edit: I moved the tic and toc to after the array initialization and before displaying x to not include that as I realized calling distributed is taking longer while it distributes the array across the processes and gather is taking time. distributed, parallel computing, spmd, parallel computing toolbox MATLAB Answers — New Questions

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