|
[Sponsors] |
memory calculation of variables in FORTRAN codes |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
April 8, 2002, 11:47 |
memory calculation of variables in FORTRAN codes
|
#1 |
Guest
Posts: n/a
|
Please tell me how to calculate the RAM required based on the dimensions to be used in a FORTRAN code
* For example, what memory in bytes will the dimension variable vx(21,21,61) occupy in a FORTRAN code on a Pentium machine. * What is a 64 bit and 124 bit machine. How does it come into picture while calculating the memory requirements of a dimensioned variables say vx(21,21,61) * How does one calculate the FLOPS of a computer. How many flops does PI, PII, PIII, PIV have. Thanks John |
|
April 8, 2002, 15:13 |
Re: memory calculation of variables in FORTRAN cod
|
#2 |
Guest
Posts: n/a
|
For x86, Digital Fortran complier:
integer --> 4 bytes real(4) --> 4 bytes real(8) --> 8 bytes so, the mem size of vx is: 21x21x61x4 = 107,604 bytes. But one can't take it for granted that 64-bit CPU will double the mem size of such data types. You have to check the documents of the compiler. To calculate the FLOPS, you'd better use assembly language and try to use registers only which can minium the memcpy time. Alternative way is download CPU test software, such as Wintune, WinBench, WCPU... |
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Comparison between C/C++ and Fortran? | rick | Main CFD Forum | 45 | September 6, 2011 01:52 |
Run-Time memory conifguration Error | Graeme | CFX | 1 | February 21, 2006 00:04 |
why Fortran? | Matteo Manganelli | Main CFD Forum | 26 | February 22, 2000 17:53 |
'C' or FORTRAN or 'C++' | Yogesh Talekar | Main CFD Forum | 20 | October 21, 1999 05:00 |
fortran codes in windows? | Thorsten | Main CFD Forum | 0 | September 24, 1998 08:51 |