When running on a Sun (Unix) workstation, the following code takes about 500MB of RAM! 
foreach $x (0..4000) {
       foreach $y (0..4000) {
             $matrix[$x][$y] = 1.0;
       }
}

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This seems like an insanely large amount. :)

Here's why I think that ... A 4001x4001 array has approximately 16,000,000 elements. If each element is a float (which is the case here) then if one assumes a 4 byte float (which is the case on my machine), you would need 64,000,000 bytes to hold them in contiguous memory. That's 64MB (right? I'm not making some silly math mistake am I??). So even if somehow each float takes 8 bytes, that's still just 128MB.

Perl uses 500MB for this. Now, I can accept the idea that there is some overhead involved, but not hundreds of MB.

Why does this take up so much memory? Equally important, how can I do this and use less memory?

Thanks!

In reply to why does this array take up so much memory? by Anonymous Monk

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