[petsc-users] how good is PETSc+GPU's ?

[Barry Smith]

On Apr 22, 2011, at 3:44 PM, Gaurish Telang wrote:

> I would like to know how well PETSc works with GPU's and the kind of Speed-ups one can get if one uses PETSc along with GPU's. 
> 
> Has it been used for scientific studies so far? 
> 
> [ I think this bit of information ( http://www.mcs.anl.gov/petsc/petsc-as/documentation/faq.html#gpus ) has been that way for a long time, and hence the above question. 
> 
> This 2010 article( http://www.mcs.anl.gov/petsc/petsc-2/features/gpus.pdf ) does n
> ot mention any comparative studies of the preliminary implementation of PETSc for use with GPU's with other software libraries. ]
> 

    There are no such studies. PETSc uses the CUSP and THRUST libraries of Nvidia on the GPU therefor the performance will be the same as using CUSP and THRUST directly or of any other library that uses CUSP and THRUST. Just like with regular CPUs the performance of sparse matrix iterative methods (floating point speedwise) is determined by the hardware so there won't be much difference between different libraries that do the "right thing".

   If you are trying to decide between two packages to use for solving some algebraic systems you need to compare them yourself, you cannot rely on what people say. If you are deciding between using a package and doing it yourself you might as well use the package since you can always add whatever custom stuff yourself if you think it is better, so there is really no downside to using a package.


   
   Barry

> Sincere thanks,
> 
> Gaurish