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sjjaber December 4, 2004 10:27

Fluent/Unix vs. Fluent/Windows
Hi! we use Fluent6.0 under unix on HP server ( we use reflection X to communicate with windows). my company wants to move to Fluent windows version, to use MicroSoft capabilites especially in postprocessing part of CFD.

anyone has experience/thoughts regarding this matter? do you think it is a wise move?


ap December 4, 2004 21:01

Re: Fluent/Unix vs. Fluent/Windows
No, I don't think it's a good choice. My reasons are not related to FLUENT, which works almost in the same way on both platforms, but rely on the difference between the two operating systems.

There are many good reasons to stay on Unix or Linux:

1) Unix and Linux are more secure and stable. Almost all vulnerabilities tipical of the Windows systems are absent on Unix and Windows.

I don't trust Windows and I won't do my calculations on a Windows system, expecially if they are a reserved work.

Windows is too vulnerable to net attacks due to its architecture, which is too much integrated with Internet Explorer and suffers of its bugs.

2) Windows is frequently patched, and all system patches requires a reboot of the system. It's really boring to reboot while you're working.

3) Windows requires additional antivirus and antispyware software, which uses system resources to do its work and subtract them to your calculations. Also consider their licence cost and the time required for their upgrades. If you properly set up your unix system, with a strong firewall configuration, you can forget antivirus.

4) Unix and Linux are more efficient in managing system resources, expecially on a server system. Windows usually slows down with usage.

5) Windows file system requires defragmentation. Unix and Linux filesystems don't! So, you don't need to spend your time to defragment your disk, if you stay on Unix/Linux.

6) All major CFD software and postprocessing tools, together with a wide range of mathematical and scientific software are available for both Windows and Unix/Linux.

I could go on for long time.

I don't know what specific software your company needs, but probably there is the same software or a similar one for Unix.

What are Microsoft capabilities which are absent on your Unix system? What tools do you need?



Rob Hart December 5, 2004 19:48

Re: Fluent/Unix vs. Fluent/Windows
There are advantages of both platforms, but I think a lot depends on the users involved.

Personally I prefer unix, but I know a lot of people aren't really at home with it, so don't get the advantages out of it.

How many fluent users do you have? and what are their opinions? Why does the "company" want to move to windows?

There are a number of potential problems if you need to transfer existing cases and data files from one platform to the other, but nothing you can't overcome.

Andrew Garrard December 6, 2004 06:16

Re: Fluent/Unix vs. Fluent/Windows
I concur with ap.

I have used both Fluent on both operating systems and not noticed much difference in the functionality. I now run all my work on a RedHat system.

The only advantage I can see windows having is it's "user friendly" interface. I am not an experienced Linux user, but it really isn't that difficult to learn enough basics to install and execute fluent, manage your files and set up your security. The performance pay offs are noticeable as well as all the other points raised in ap's post. And, should your company need more convincing, the best bit is that it is entirely free.

Evan Rosenbaum December 6, 2004 13:12

Re: Fluent/Unix vs. Fluent/Windows
We are actually considering the opposite migration. Some of our recent models have pushed GAMBIT to its limits. We has all sorts of trouble that didn't occur on FLUENT's linux machines but did on our PCs. I think (my personal opinion) there were two reasons.

1. FLUENT develops on linux. The PC versions are ports, and subject to more bug potential because of the extra operations.

2. Windows memory management is not as good as linux.

Many of the problems we had on the were not reproducible by FLUENT's tech support under linux, but were reproducible by them on PCs.

ap December 6, 2004 17:58

Re: Fluent/Unix vs. Fluent/Windows
Yes, I forgot to mention this. Windows version has some problem which are absent on Linux.

Morover, GAMBIT run under eXceed X emulator on Windows, which adds potential problems and requires additional resources.


ap :-D

zxaar December 6, 2004 20:46

Re: Fluent/Unix vs. Fluent/Windows
there is one more problem on windows ... often when after a big run you are trying to visualise the results and suddenly fluent will hang, and the only way out then be to lose your run, because of this i always save my files first before touching the post processor (but it sucks to be insecure)

ap December 7, 2004 18:39

Re: Fluent/Unix vs. Fluent/Windows
Right, you're not secure on the net, you're not secure while working.

That's the essential point: on Windows you're not secure.


yot December 11, 2004 06:53

fluent installation in linux
We have installed fluent in linux system, but we don't know how to set the license,environmental variables etc., please help us.

Samir January 5, 2005 14:56

Re: Fluent/Unix vs. Fluent/Windows
Hi guys,

I recently switched to Linux and am using StarCd on it. I am trying to install Fluent too. But the platform compatibility chart says its not compatible with a 64 bit pentium/ Xeon processor. I tried installing it, but it gives me an error saying: $ fluent /Fluent/Fluent.Inc/fluent6.1.22/cortex/lnx86/cortex.3.5.6 -f fluent (fluent " -path/Fluent/Fluent .Inc") /Fluent/Fluent.Inc/fluent6.1.22/cortex/lnx86/cortex.3.5.6: error while loading shared libraries: l cannot open shared object file: No such file or directory

Does any of you have an idea what this means?. Thanks in advance. Regards Samir.

ap January 5, 2005 17:58

Re: Fluent/Unix vs. Fluent/Windows
Probably you're using Red Hat Linux (> 7) or Fedora Core.

The problem happens beacause Red Hat uses a different version of the libstdc library.

I had the same problem, and I solved it by just installing the proper version of libstdc.

This can be done by installing the RPM compat-libstdc++

If you're using RedHat or Fedora Core, look here:

P.S. The problem doesn't exist on other Linux distributions like Novell SuSE Linux, which is, in my opinion, easier to use, more powerful and more supported.

Regards, ap :)

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