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Re: max. array size GNU C compiler...
- To: help-gcc at gnu dot org
- Subject: Re: max. array size GNU C compiler...
- From: EKK <ekk at ekkinc dot com>
- Date: Fri, 20 Aug 1999 08:45:07 -0700
- Newsgroups: comp.lang.c,comp.os.linux.setup,comp.os.linux.misc,comp.os.linux.alpha,gnu.gcc.help,comp.lang.fortran
- Organization: EKK Inc
- References: <37BC4252.F83CD3E@ekkinc.com> <87r9kzebjj.fsf@pfaffben.user.msu.edu> <37BC4A9E.D3CC7FEC@ekkinc.com> <7pi0je$knv$1@nnrp1.deja.com>
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> Some compilers put static and dynamic memory in different areas. Some
> compilers have limitations on static memory size, but the limit on
> dynamic memory is based on the amount of memory in the machine.
>
it seems under IRIX, the limit is the system's stacksize, which you
can only change to the corresponding physical RAM and not beyond.
the stacksize on my Linux box is 'unlimited'...perhaps the limitation
is not in the system, but the compiler????
I've tried with an array that exceeds the physical 512MB of memory on
the Linux box. The compiler does not seem to complain untill
beyond 1GB, but well before 2GB. It's pretty hard to tell, I guess
without a machine with 2GB of physical RAM on it, but I am trying
to decide whether to buy one or not, so...
> An N-bit machine does not guarantee that it contains a lot of memory.
> If I have an 8-bit machine with 32M of memory and a 64-bit machine with
> 16 megs of memory, what does this tell you? The N-bit machine can
> ACCESS a wider range of memory than an M-bit machine, provided that M <
> N.
>
> Another question is: Do you really need all those values in memory at
> the same time? Can you store the values in a file and only haul in
> small pieces that you are working on? {Works with matrices, and tables}.
>
this would be a good thing, however, this is a finite element analysis
code which would need a massive overhaul to achieve what you describe
above, which would induce considerable loss of performance.
thank you,
AG
--
Alessandro Giachino, Software Engineer
EKK Inc.
2065 West Maple C309 tel. 248-624-9957
Walled Lake MI 48390 fax. 248-624-7158
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