I noticed this problem late 2016 while investigating scan overhead. Check 
here 
<https://github.com/Theano/libgpuarray/issues/292#issuecomment-262696507>. 
The comment also have a link to a script help reproducing the problem.

On Friday, February 17, 2017 at 7:43:39 PM UTC+8, Ozan Çağlayan wrote:
>
> Hi,
>
> With the current Theano HEAD + libgpuarray, I launched two RNN-based MT 
> systems with the old backend and the new backend and apparently the new 
> backend is a little bit slower than the old one.
>
> This is on CUDA 7.5, CUDNN5.1 and Tesla K40 GPU, batchsize=64:
> old backend: 166ms / batch
> new backend: 186ms / batch
>
> On a moderate 4M sample dataset, this would bring an overhead of ~20 
> minutes per epoch.
>
> Is this expected? If yes, why would I prefer the new backend?
>
> Thanks.
>
> -- 
> Ozan Çağlayan
> Research Assistant
> Galatasaray University - Computer Engineering Dept.
> http://www.ozancaglayan.com
>
> #HayırdaHayırVar
>

-- 

--- 
You received this message because you are subscribed to the Google Groups 
"theano-users" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
For more options, visit https://groups.google.com/d/optout.

Reply via email to