[Insight-users] [Insight-developers] Cuda ITK

[Badri Roysam]

We invested heavily in GPUs and CUDA in my lab a couple of years ago. Our practical
experience has been that these things don't work quite as we had imagined from the
advertising. In other words, when we compiled our vessel segmentation codes on CUDA,
we found no speedup (in some case, it was slower than optimized compilation on the CPU.
It took a lot of work to get speedup over serial code. You have to rethink your
code to suit a streaming architecture, and spend time working out the data flows carefully.
Overall, we learned that the effort involved in building 
"GPU versions" of existing routines is
manpower intensive. I am interested to know what others' experience has been.


Badri Roysam
Professor, Department of Electrical, Computer and Systems Engineering
Associate Director, NSF Center for Subsurface Sensing & Imaging Systems (CenSSIS ERC)
Co-Director, Rensselaer Center for Open Source Software
Rensselaer Polytechnic Institute
110 8th Street, Troy, New York 12180-3590, USA.
Office(JEC 7010): 518-276-8067, Assistant: 518-276-8525, Lab(JEC 6308): 518-276-8207, Fax: 518-276-8715
Email: roysam at ecse.rpi.edu, Web: http://www.ecse.rpi.edu/~roysam



----- Original Message -----
From: Dan Mueller [mailto:dan.muel at gmail.com]
To: Gaëtan Lehmann [mailto:gaetan.lehmann at jouy.inra.fr]
Cc: ITK Users [mailto:insight-users at itk.org], ITK Developers [mailto:insight-developers at itk.org]
Subject: Re: [Insight-users] [Insight-developers] Cuda ITK


> Hi Gaetan,
> 
> I too have been following the closely development of the GPGPU field
>     http://en.wikipedia.org/wiki/Gpgpu
> and waiting for ITK to jump on board (unfortunately I have had little
> spare time to spearhead this myself).
> 
> I remember speaking to Luis at a t-con last year about ITK+CUDA and he
> mentioned one of outcomes of the project was discovering that CUDA is
> not (yet) very portable (i.e. code that works on one NVIDIA card, does
> not necessarily work on another).
> 
> If ITK is going to be GPGPU-enabled, then perhaps the OpenCL standard
> will provide more portability:
>     http://en.wikipedia.org/wiki/OpenCL
> 
> Obviously OpenCL is still new (version 1.0 approved December 8, 2008),
> but I imagine we'll start seeing supporting hardware soon
>     http://www.nvidia.com/object/io_1228825271885.html
>    
> http://news.softpedia.com/news/AMD-Takes-Up-OpenCL-1-0-Puts-More-Effort-on-ATI-Stream-SDK-99578.shtml
> and maybe even Intel's Larrabee
>     http://www.hpcwire.com/blogs/OpenCL_On_the_Fast_Track_33608199.html
> 
> (I don't think NVIDIA or ATI has to date officially announced a chip
> with OpenCL support...I'd be happy to be proved wrong...)
> 
> Because much of this is still speculative, it doesn't really factor
> into your discussion about what hardware to buy today... Just a
> warning: while CUDA is the pioneer, it may not be be around to see the
> real action.
> 
> Cheers, Dan
> 
> 2009/2/11 Gaëtan Lehmann <gaetan.lehmann at jouy.inra.fr>:
> >
> > Hi,
> >
> > We are currently thinking to buy a few powerful workstations to run ITK in
> > my lab.
> > I heard of nvidia's tesla cards, and I see that some experiments has been
> > made to use them in ITK.
> >
> > http://www.na-mic.org/Wiki/images/f/f9/Itk-gpu-meeting-Fall2007.ppt
> >
> > Is there any update since fall 2007?
> >
> > Regards,
> >
> > Gaëtan
> >
> >
> > --
> > Gaëtan Lehmann
> > Biologie du Développement et de la Reproduction
> > INRA de Jouy-en-Josas (France)
> > tel: +33 1 34 65 29 66    fax: 01 34 65 29 09
> > http://voxel.jouy.inra.fr  http://www.mandriva.org
> > http://www.itk.org  http://www.clavier-dvorak.org
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