[Haskell-cafe] Data.Array.Accelerate initialization timings

[Paul Sujkov]

Hi Alex,

I've seen that method, but I don't see how can I use it for initialization
purposes. It creates Acc (Array e i) from Array e i, but what should I do
while I don't have Array yet? And when Array is already initialized, 'use'
will transfer it to GPU memory which will add some extra timings, but won't
optimize what I have at the moment.

However, I'll try to use it somehow. Maybe I misunderstand the mechanics.
Thanks a lot!

On 20 February 2012 16:06, Alex Gremm <algremm at googlemail.com> wrote:

> Hi Paul,
>
> even though I just started reading about Accelerate, it seems to me that
> you didn't use the "use" method which according to [1] initiates
> asynchronous data transfer from host to GPU.
>
>
> Cheers,
> Alex
>
> [1]: http://www.cse.unsw.edu.au/%7Echak/papers/acc-cuda.pdf
> On 20/02/12 14:46, Paul Sujkov wrote:
> > Hi everyone,
> >
> > since accelerate mail list seems to be defunct, I'm trying to ask
> > specific questions here. The problem is: array initialization in
> > Data.Array.Accelerate takes a 10x amount of time in contrast to both
> > Data.Array and bare C++ CUDA array initialization. This can be due to
> > Data.Array.Accelerate having two backends (however, it's own tests show
> > that my nVidia card is CUDA-capable), but I'm not aware of how can I
> > profile GPU to check whether it is used or not. Anyway, here's code:
> >
> > http://hpaste.org/64036
> >
> > both generateArray (DIM3) and generateArray1 (DIM1) take the same amount
> > of time to initialize array. I'd say the problem is in GPU memory
> > copying time, but here's bare C++ code:
> >
> > http://hpaste.org/64037
> >
> > which does exactly the same, but 10 times faster. I'm wandering what am
> > I doing wrong and how to check if I really am. Thanks in advance if
> > anyone can point me on my mistakes!
> >
> > --
> > Regards, Paul Sujkov
> >
> >
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>
>


-- 
Regards, Paul Sujkov
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