[Chris Lee]

Hello forum members,
I am trying to order a computer today for doing computational analysis.
This will be a dual-boot system, so that I can run some programs on Linux and some on Windows.

I would like to take full advantage of multi-processors for running
CFD (like SU2 code, and Overflow, and maybe Openfoam) and
AutoDesk ( to whatever extent it uses parallel processing).

When I tried using multi-processors for SU2 on my current system I ran into an issue with the setup which basically told me that I needed Windows Server 2008 to handle the multi-processor function.

The question is, for my new system, which operating system should I be getting? The choices from the computer builder are:

Windows 8.1 Pro 64-bit
Windows 7 Pro 64-bit
Windows 7 Ultimate 64-bit
Windows Server 2012 Essentials

I was going to pick 7 Ultimate,
but I'm thinking I might need Server.
I'm concerned that Server 2012 has lost some attributes compared to Server 2008 r2.

Can someone please help me understand which operating system I need?
Thanks!

P.s.
The system will be a Xeon processor based mobile workstation, with
6, 10 or 12 cores (e.g. Xeon E5-1660 v2, or up to Xeon E5-2697 v2) and
32GB RAM (only DDR3 available, unfortunately. no DDR4 yet) and
a couple of SSDs (Samsung model 850 512 GB x 2) and
Nvidia Quadro 5100M video card.

[acasas]

Don't waste your money in xeon, use i7

[Chris Lee]

i7 options only go up to 6 cores. (at least for this mobile workstation)
I am shooting for 10 or 12.

also, i'd heard the i7 chips don't support ECC RAM,
(and I'm assuming this RAM is ECC in this system . . . though I'm trying to confirm that now)

i have to admit I have not dug into this much lately, but almost every informed opinion I read a couple months ago said to go Xeon for high performance/multi-processor computing . . . especially for applications like CFD (anyalyzing airflow on 80M grid points) where inter-core communication speed / reliability is of the essence.

Can you explain more why you recommend the i7 over Xeon?
Thanks.

[acasas]

Originally Posted by Chris Lee

i7 options only go up to 6 cores. (at least for this mobile workstation)
I am shooting for 10 or 12.

also, i'd heard the i7 chips don't support ECC RAM,
(and I'm assuming this RAM is ECC in this system . . . though I'm trying to confirm that now)

i have to admit I have not dug into this much lately, but almost every informed opinion I read a couple months ago said to go Xeon for high performance/multi-processor computing . . . especially for applications like CFD (anyalyzing airflow on 80M grid points) where inter-core communication speed / reliability is of the essence.

Can you explain more why you recommend the i7 over Xeon?
Thanks.

Yes, check this out http://www.cfd-online.com/Forums/har...-3930k-x2.html

http://www.cfd-online.com/Forums/har...5-2650-v3.html

http://support.microsoft.com/kb/2155311

And when I do run the intel processor diagnostic tool 64 bits on my 2 xeon e-5 2650 v3, it shows a big red FAIL ! for the QPI which is the "bus"

[wyldckat]

FYI:

1. Detailed explanation to acasas' problem has been given at post #5 here: http://www.cfd-online.com/Forums/har...tml#post520919
2. In addition, the comparison done at the thread http://www.cfd-online.com/Forums/har...-3930k-x2.html - is unfair, as pointed out by the posts after the first one, because the i7 was better in everything.

[acasas]

Originally Posted by wyldckat

FYI:

1. Detailed explanation to acasas' problem has been given at post #5 here: http://www.cfd-online.com/Forums/har...tml#post520919
2. In addition, the comparison done at the thread http://www.cfd-online.com/Forums/har...-3930k-x2.html - is unfair, as pointed out by the posts after the first one, because the i7 was better in everything.

Yes, guys, Bruno is probably right. I will try what he suggest and post results in here. Sorry if I did confuse someone with my post. Please try to imagine how I did felt, and how nervous I was.

thanks a lot

[Chris Lee]

Originally Posted by acasas

Yes, guys, Bruno is probably right. I will try what he suggest and post results in here. Sorry if I did confuse someone with my post. Please try to imagine how I did felt, and how nervous I was.

thanks a lot

Indeed. Yes, and thanks for hijacking the thread.

So, my original question was . . .
which operating system do I need (not which CPU should I buy).

In particular I am going to be running some software which only runs on linux (Overflow) and some that runs on Windows (Office, in addition to some CAD and other computational s/w).

Also, I've had issues with file translation between linux based systems and windows, and I imagine I might make good use of the "Subsystem for Unix-based Applications" which is available in Windows 7 Ultimate.

With regard to the Windows, . . . and because I want to run the SU2 software from Stanford in parallel mode . . .
and because the install guidelines point out that I need to install Microsoft's HPC Pack 2012 . . .
and because MS HPC Pack 2012 r2 says that it supports only certain versions of MS Windows . . .

I'm wondering which MS Windows OS I really need.

Anyone out there from the SU2 camp want to weigh in on this?
Do I really need HPC to run SU2 in parallel?
Do I need Windows Server to handle the HPC Pack, or will Windows 7 Ultimate handle it. (I don't need to farm the work out to separate machines on a network, I just want to take advantage of all the cpu cores on my system.)

Thanks for your input!

[flotus1]

Maybe you will find some of the answers regarding the Windows operating system here

Edit: what exactly do you mean by "file translation between Linux based systems and Windows"?

[Chris Lee]

Originally Posted by flotus1

Maybe you will find some of the answers regarding the Windows operating system here

THanks, flotus1.
I had read some of that OS information on Microsoft's website.
I'm still left wondering, however, if I need to run MS's "HPC Pack" (which is downloadable for free) to take advantage of multiple cores on one or two physical processors on my own system.

Assuming I need HPC Pack to use multiple cores on my own single system . . .
Where things get foggy for me are in the HPC nomenclature.

If an HPC architecture is required to have at least one "head node",
then it appears I need Windows Server OS. (see the Question "What operating systems does Microsoft HPC Pack 2012 support?" under this link.)

If, however, I can have a simple HPC architecture where my own workstation is a "workstation node"as the only system involved (and no "head node" is needed), then it appears I can get by with Win7 Pro, Enterprise, or Ultimate.

Any experts out there in HPC architecture/nomenclature?

[Chris Lee]

Originally Posted by flotus1

Edit: what exactly do you mean by "file translation between Linux based systems and Windows"?

I went through a lot of trouble getting around the infamous line termination disparity between unix and windows.
For example, I copied and input file for SU2 which had been created on a unix system, and tried to use it on my windows system.
It did not read the file properly.
After trying some utilities aimed at fixing this issue (e.g. "tofrodos")
i still ended up having to manually edit the files, line by line, to get it to read properly. It was a RPITA. (Royal Pain In The . . .)

I'm hoping that I can use the "SUA" feature available in Win7 Ultimate to get around that kind of issue.

[huey1080]

Hi Chris,

You are confusing head node as a machine and head node as a process. When running CFD codes in parallel, one process is the head node and the others are parallel processes. You can run CFD codes in parallel on the same machine without the use of Windows HPC. What Windows HPC and other cluster manager are doing is allowing processes (parallel processes) to be run on another machine. So if you have 2 machines for example, you can have one as a head node (because the head process is running on it), several parallel processes on the head node machine and parallel processes on the other machine.

[wyldckat]

Greetings to all!

I'll be trying to answer most of Chris Lee's questions in this post. For reference, questions related to the system configuration itself, were answered here: http://www.cfd-online.com/Forums/har...tml#post523854 post #18

Originally Posted by Chris Lee

When I tried using multi-processors for SU2 on my current system I ran into an issue with the setup which basically told me that I needed Windows Server 2008 to handle the multi-processor function.

I see you asked this on the respective forum and didn't get an answer: http://www.cfd-online.com/Forums/su2...llel-mode.html - please do keep in mind to post on that thread when you finally figure out the solution, based on the feedback written here.

Originally Posted by Chris Lee

The question is, for my new system, which operating system should I be getting? The choices from the computer builder are:

Windows 8.1 Pro 64-bit
Windows 7 Pro 64-bit
Windows 7 Ultimate 64-bit
Windows Server 2012 Essentials

I was going to pick 7 Ultimate,
but I'm thinking I might need Server.
I'm concerned that Server 2012 has lost some attributes compared to Server 2008 r2.

Can someone please help me understand which operating system I need?

Honestly, between all of those versions, what you'll be getting different is the maximum number of cores usable and maximum RAM usable:

• Maximum RAM per Windows version: http://msdn.microsoft.com/en-us/libr...=vs.85%29.aspx
• Maximum number of cores... er, I can't find any reference. The best I could find was that the Pro versions support dual socket motherboards, while the non-pro versions only support one socket. Beyond that, looks like up to 32 logical cores might be supportable.
  Server versions are meant to allow more than 2 CPU sockets... and more than 64 logical cores can get a bit strange, depending on the Windows version.

A side note about "Windows Server 2012 Essentials": based on the RAM limits indicated in the page above, it looks like this particular version is somewhat crippled. I guess they created it for people that use workstations with 2 CPU sockets or more, but with only 64GB of RAM at maximum.

Originally Posted by Chris Lee

Also, I've had issues with file translation between linux based systems and windows, and I imagine I might make good use of the "Subsystem for Unix-based Applications" which is available in Windows 7 Ultimate.

I'll address later below, in an answer to another quote.

Originally Posted by Chris Lee

With regard to the Windows, . . . and because I want to run the SU2 software from Stanford in parallel mode . . .
and because the install guidelines point out that I need to install Microsoft's HPC Pack 2012 . . .
and because MS HPC Pack 2012 r2 says that it supports only certain versions of MS Windows . . .

I'm wondering which MS Windows OS I really need.

I don't have experience with SU2, but I think you can easily simply install MS-MPI: http://www.microsoft.com/en-us/downl....aspx?id=44990 - it's the core needed for using MS-MPI, namely for running the applications in parallel.
The HPC Pack is only a convenience package that provides the job scheduler and other tools, to assist in using more than one machine and when running more than one job.

You can also try installing the HPC Pack SDK: http://www.microsoft.com/en-us/downl....aspx?id=36043 - which roughly supports any Windows version

Originally Posted by Chris Lee

If an HPC architecture is required to have at least one "head node",
then it appears I need Windows Server OS. (see the Question "What operating systems does Microsoft HPC Pack 2012 support?" under this link.)

As huey1080 mentioned, "head node" is only needed in a cluster, since it's the main computer that manages all of the worker computers (worker nodes). Since you'll only be using a single workstation, you don't need Windows Server.

Originally Posted by Chris Lee

I went through a lot of trouble getting around the infamous line termination disparity between unix and windows.
For example, I copied and input file for SU2 which had been created on a unix system, and tried to use it on my windows system.
It did not read the file properly.
After trying some utilities aimed at fixing this issue (e.g. "tofrodos")
i still ended up having to manually edit the files, line by line, to get it to read properly. It was a RPITA. (Royal Pain In The . . .)

I'm hoping that I can use the "SUA" feature available in Win7 Ultimate to get around that kind of issue.

Uhm... ever heard of Cygwin and/or MinGW (specifically MSys)? Because "SUA" is pretty much a crippled and outdated implementation of technologies that MinGW/MSys and Cygwin are much better at and have been doing it for several years now. Using SUA is only a last measure, in case your company's IT department does not allow installing Cygwin or MinGW/MSys.

dos2unix and unix2dos are the usual application names for changing line endings, which are usually also available on Linux, in case you don't want to mess with them on Windows.
There is also Git (MSys+Git for Windows), which can automatically fix line endings when you pull the latest file version from the shared source code version repository. Takes a while to learn how to use it, but you'll end up being grateful for keeping an historical log of the changes you make to your input files and simulation set-ups... assuming that you strictly abide to the necessary work-flow ethic.


You might also want to request the developers of SU2 to support both line endings on each operating system.

Better yet, if you're worried only about the input file (i.e. text files), on Windows you can for example use Notepad2 or Notepad++ to easily change between line endings for files.


Hopefully I didn't miss any question.

Best regards,
Bruno