[maka]

If the processor is AMD but NOT 64 which version should we use:

Pentium Linux
AMD Linux 64bit

I would be grateful if briefly describe the main difference between the two distribution, by that I mean:

which files handle such difference between processors?

Is it just the compiler options or more?

Regards,
Maka

[maka]

sorry, I posted here by mistake

[henry]

The 32bit release is for 32bit AMD and Intel processors and AMD 64bit processors for those who wish to run in 32bit mode.

The 64bit release is for AMD 64bit processors.

The difference between these two builds is just the compiler options which are in the sub-directories of OpenFOAM-1.?/wmake/rules.

[maka]

Hi Henry,

Our cluster incude two cluster one 32 bit and one 64 bit. If I install 64bit release, can I use the flag WM_64="on" to switch between 32 and 64 or I also need to recompile the code every time I switch?

Also, the name of the folder for 3rd party binaries, should I use linux on linuxAMD64 or create two folders, since the name is mostly referenced in some pathes.

The main thing is to make switching between 32 and 64 with one installation is easy, since using either depends on which processors are free at the moment.

Many thanks for your answers,
Maka

[maka]

Detailed procedure:

I though that posting this may be helpful to beginners:

using bash:

refere to : README and B. Running OpenFOAM in 64 bit mode in the README file;
Make OpenFOAM directory in you home and inside it do the following:

(1) Unpack the General file the optional files (both 32 bit and 64 bit);
(2) Make 2 {platform} folders: linux and linuxAMD64 for 32 and 64 bit respectively. Unpack the 3rd party 32 bit and 64 bit binaries in them respectively;
the rest is as in read me;

To switch to 32 bit mode:
(1) Go to a 32 bit processor;
(2) uset $WM_64;
(3) source ~/.bashrc, it reads the $processor type, that is why step (1) is necessary;

to swith to 64 bit mode:
(1) Go to a 64 bit processor;
(2) export WM_64="on"; to check type WM_ then tab;
(3) source ~/.bashrc, it reads the $processor type, that is why step (1) is necessary;