[Beowulf] re: Quick question... on Fortran

Matt rosing at peakfive.com
Thu May 10 09:59:19 PDT 2007


>I am (as you may well know) extremely fortran averse.  However, a
>researcher in our department has recently asked what the current limits
>are on the size of an array in modern fortran(s) under linux.  I suppose
>he'd like an answer for both 32 and 64 bit systems.  From what I have
>been able to google out, it looks like the answer is 2^31 bytes in 32
>bit systems and as big as the hardware permits less maybe a GB in 64
>bit

The limit is 2GB for Intel ia-32 compilers, fortran or not. You may
need to compile -static to get it. Since this is half the 4GB limit of
a 32 bit system (maybe the last bit is lost because of signed
arithmetic?), I'm guessing the ia-64 compilers can have much larger
arrays.

Fortran90 doesn't say anything about array limits.

Matt




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