[CAVT]

Hi all.
Usually Windows and Linux are heavyweights when it comes to industrial applications, with Mac popping from time to time. Personally I have only worked with Windows and Linux, being the latter my preferred choice.
Now, just to change the old discussion between Linux and Windows, I would like you to share your experience and opinions about the suitability of other OSs for engineering uses (mostly related to CFD, but other situations should also be considered). In particular I think of the following options:

BSD and its variants (FreeBSD, OpenBSD, NetBSD, DragonflyBSD). It's able to run many Linux apps and is quite light.
Solaris, specially its open-source variants OpenSolaris and Ilumnos. Apparently for what I read, it's a nice option for clustering, but compatibility looks a bit restringed.
Mac OS X. It's BSD based, and has a good reputation of robust and fast.
Aix, HP-Ux, other *nixes. Usually variants of Unix for specific architectures.

Thank you.

César

[jola]

Today Linux and Windows are completely dominating. Only a very small fraction of CFD users use a different OS. The only non-Windows/Linux OS with a bit of a user base is Macintosh - 4% of all traffic on CFD Online come from Mac users. You asked about BSD - the statistics from CFD Online show that only 0.02% of all users have BSD as OS. For further details see the operating system statistics from visitors to CFD Online in 2010:

http://www.cfd-online.com/Stats/#os

This can be compared to how it looked back in 2000:

http://www.cfd-online.com/Stats/2000_Jan-Jun/#OS

Back then IRIX and SunOS was more common than Linux.

[CAVT]

Well, it's more or less what I expected, but I'm still surprised by the evolution Linux had. Any ideas why this could happen? I suppose it has to do with lowering costs, wide array of architectures covered and compatibility with Windows, but for example Solaris is the replacement for SunOS, and it also has Open Source versions, so at first I don't see a reason to leave it. Also, why does Mac has such low numbers? Or better said, why do developers leave aside Mac, given its reputation of a solid OS?.
Meanwhile, I know that Code_Saturne can be run on Solaris successfully, and I think the largest simulations where made under Solaris in Sparc clusters.

[jola]

The very quick development of PC hardware together with the stability of Linux made it a very good CFD platform. I remember back in 1999, when we put together our first Linux cluster. Before that we had been running HP-UX. For a few weeks over summer we borrowed 12 PC's from the IT department that were intended to be placed on peoples desktops as Windows machines after vacation. We buildt and benchmarked a Linux cluster made up of 12 $1500 machines. This cluster could run in circles around our HP-UX compute server, that had cost us $120,000.

It could have become BSD instead of Linux. I think the main reason is the people behind and their willingness to include contributions from other people and distribute their OS freely without any restricting license.

Solaris didn't become free until Linux had already won the game. Similarly, Mac OS-X didn't exist when Linux grew so quickly.

[andyj]

Hello!
I have used Sun Solaris on a personal computer. . It is simply the fastest operating system I have ever seen on a PC. So fast that its almost alarming. Oracle has now bought Solaris. Which is just as good as Sun from a users standpoint of having lots of developers behind it.
It was designed and intended for large arrays of mainframe computers in enterprise enviroments. Several states in the US use it for their system, as do many large corporations. Can run 10,000 clients from a Solaris server array. Its big iron software. Mainframe stuff.
Although used moslty for business databases, since it is so fast, it has been adapted to timing chemical reactions and other scientific applications.
The positives are its speed, power, complete documentation and the number of employees developing and supporting it. I believe Solaris holds the world speed record for floating point calculations.
Solaris disadvantages are hardware compatibility and software compatibility. For example, high quality Intel network cards are compatible. Hardware compatibilty has improved recently. You would probably only need to load portions of the operating system to use it for science applications. Careful study would be needed to install for science application rather than business. About 11 Gb for a full install, which is the easiest, accept all default install settings. Oracle Solaris would be what you want, as the free version is in dispute, and was never as good as the paid Sun version.


As far as Mac is concerned, its a consumer OS, but not used much in Engineering. Documentation is nowhere near the completeness seen in Microsoft, Microsoft Technet, Knowledge base and MSDN support.


I like Windows, Linux. Of the 500 fastest supercomputers, 66 run Suse Linux. Solaris is used on some. I am unsure what the most popular supercomputer OS is. Depends on what software application uses which operating system. But the availability of documentation is essential, unless the end users are clairvoyant. Same thing applies to all open source software...how good is the documentation?
I never understood why Sun or Oracle never released a consumer desktop OS, and stayed focused on big iron.

[jchawner]

FWIW, here are my experiences. We've seen a surge of interest in Mac OS X as a platform for CFD. People like that it's Unix at its core, it's not Windows, and its not open source. (Really, some people prefer using a professionally supported OS - and yes, I know you can get support for Linux.) OS X also provides good performance.

Solaris is popular but its future is not clear with Oracle planning to kill Open Solaris and make the OS proprietary again.