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On 03/20/12 00:03, Mark Knecht wrote: |
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> On Mon, Mar 19, 2012 at 7:05 AM, Andrew Lowe <agl@×××××××.au> wrote: |
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>> On 03/19/12 20:34, Mark Knecht wrote: |
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>>> On Mon, Mar 19, 2012 at 5:32 AM, Mark Knecht <markknecht@×××××.com> wrote: |
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>>>> On Sun, Mar 18, 2012 at 10:26 PM, Andrew Lowe <agl@×××××××.au> wrote: |
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>>>>> Hi all, |
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>>>>> Has anyone played around with the various "better known" compilers on |
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>>>>> Gentoo? By "better known", I'm referring to gcc, Intel, llvm, pathscale. My |
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>>>>> situation is that I've just started my PhD which requires me to do Finite |
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>>>>> Element Analysis, FEA, and Computational Fluid Dynamics, CFD, and I want to |
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>>>>> find the "best" compiler for the job. Before anyone says "Why bother, XXX |
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>>>>> compiler is only 1 - 2% faster than gcc", in the context of the work I'm |
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>>>>> doing this 1 - 2% IS important. |
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>>>>> |
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>>>>> What I'm looking for is any feedback people may have on ability to compile |
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>>>>> the Gentoo environment, the ability to change compilers easily, gcc-config |
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>>>>> or flags in make.conf, as to whether the compiler/linker can use the |
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>>>>> libraries as compiled by gcc on a "standard" gentoo install and so on. |
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>>>>> Obviously there is much web trawling to be done to find what other people |
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>>>>> are saying as well. |
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>>>>> |
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>>>>> Any thoughts, greatly appreciated, |
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>>>>> Andrew Lowe |
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>>>>> |
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>>>>> |
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>>>> |
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>>>> Think CUDA |
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>>>> |
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>>>> Mark |
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>>> |
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>>> Sorry. Meant to include this reference: <$15 on Kindle. Reads great on |
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>>> Kindle for PC. |
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>>> |
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>>> http://www.amazon.com/CUDA-Example-Introduction-General-Purpose-ebook/dp/B003VYBOSE/ref=sr_1_4?ie=UTF8&qid=1332160431&sr=8-4 |
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>>> |
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>>> |
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>> |
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>> I'm sorry but I'm doing a PhD, not creating a career in Academia. The |
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>> concept of writing an FEA or CFD from scratch, with CUDA is laughable, I |
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>> just don't have the time to learn CUDA, research the field, small |
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>> displacement, large displacement, dynamics, material nonlinearities, |
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>> write the code, and then most importantly benchmark it to make sure it's |
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>> actually correct. This is all bearing in mind that I have 20+ years |
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>> experience as a C/C++ technical software developer, including FEA and |
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>> CFD. I'll actually be using Code Aster, an open source FEA code that |
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>> runs under Linux. |
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>> |
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>> Sorry if I sound narky, but compilers is the subject at hand, not how |
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>> to write FEA code. |
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>> |
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>> Anyway, thanks for answering, |
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>> |
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>> Andrew |
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>> |
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> |
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> Nahh, be as snarky as you like as long as you don't really mean it personally. |
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> |
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> My experience with CUDA, and I'm not a programmer, is that there is a |
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> fairly steep learning curve. However changing C compilers will get you |
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> maybe 5%. Changing to CUDA will get you 30,000%, assuming a mid-high |
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> range CUDA card and that you can parallel-ize FEA. I did a little |
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> Googling and it seems that FEA is a pretty common CUDA topic so I |
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> don't think at the outset that you'd find yourself all alone. |
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> |
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> Good luck whatever you do and know that I didn't mind the response at all! :-) |
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> |
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> Cheers, |
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> Mark |
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> |
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> |
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The thing is that I agree that CUDA is the way to go for things like |
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FEA & CFD, in fact the mob that runs the super computer I'm using is |
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installing another one that is top heavy in CUDA cards. But the thing is |
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as I'm using the FEA as a tool, rather than playing around with the |
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innards of the code, I need an established code, one that has |
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verification behind it. My topic looks at the way that steel connections |
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behave so I need an established FEA code that is verified to provide the |
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correct answers, I don't get that if I write my own code. |
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Most likely I'll write a short paper covering a comparison of existing |
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C/C++ compilers and their relative speeds, spend the next 18 months - 2 |
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years doing my research and then to close things off, I'll probably be |
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able to write another short paper concerning CUDA speedups as the FEA |
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code bases will have caught up and been verified. |
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Thanks for peoples replies, |
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Andrew |
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p.s. Writing this I just had a sudden horrific though and checked the |
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FEA code I'm using, Aster. It's written mostly in FORTRAN - fat chance |
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I'm going to be hacking that code........ |
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