parfor using
1 次查看(过去 30 天)
显示 更早的评论
Hi everybody, i have a question about parfor using. I tried a classical example for parfor on my PC but i couldn't get gainly results. How ?
nmax=1000;
y = zeros(nmax,1);
tic
parfor n = 1:nmax
z = randn(n);
y(n) = max(svd(z));
end
toc
Results:
(nmax, pool size, time)
(500, 0, 12.51) (500, 2, 8.71) (500, 4, 5.16) That's OK.
(750, 0, 46.03) (750, 2, 38.65) (750, 4, 30.32) Maybe OK.
(1000, 0, 141.40) (1000, 2, 156.19) (1000, 4, 174.81) Why ?
Thanks for replies.
0 个评论
采纳的回答
Laurens Bakker
2012-3-7
Hi Yildirim,
There is considerable overhead in gathering the data back into a single variable. I removed the assignments and that improves the situation.
nmax=1000;
y = zeros(nmax,1);
tic
parfor n = 1:nmax
max( svd( randn(n) ));
end
toc
Cheers,
Laurens
0 个评论
更多回答(1 个)
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Parallel Computing Fundamentals 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!