CUDNN doesn't support the dilated convolution

[thesby]

CUDNN doesn't support the dilated convolution. I'm trying to use CUDNN engine to save GPU memory. Is it possible to use zeros to fill the dilated kernel where it shouldn't be convolved ?

[naibaf7]

Yes, but depending on the amount of fill, the performance will go way down and memory consumption up, and you need to change some code to do so. LibDNN from the OpenCL branch (can also be used with CUDA) can do dilated convolution in any dimension without additional memory. It is not as fast as cuDNN though for convolutions without dilation. But you can mix the two and change the engine on a per-layer basis.

[thesby]

But I need cuDNN to reduce GPU memory. So it's impossible now except waiting for the update of cuDNN.

[naibaf7]

@thesby libDNN uses the same amount or less memory than cuDNN, depending on the algorithm. Just the speed is not as high. So it's not impossible :)

[thesby]

@naibaf7 OK, thank you. But I found that there is no updating for a long time about libDNN. Is there any problem if I mix two conv engine -- CAFFE, CUDNN -- in conv layers in latest caffe?

[naibaf7]

@thesby LibDNN standalone wasn't updated for a while, you have to use the Caffe-opencl branch for the latest LibDNN. You can mix two engines in one network, one engine per layer. Caffe dilated convolutions will be both too slow and too memory expensive. Use LibDNN layers for your dilated convolutions, Caffe layers for inner products and cuDNN layers for convolutions with regular filters.

[thesby]

@naibaf7 Thank you. I will try it.

[shelhamer]

Note that future cuDNN is expected to include dilated convolution.

[KeyKy]

I use the following layer in training and my problem is that training is fast, testing too slow. WHY? Thanks! layer { bottom: "res5a_branch2a" top: "res5a_branch2b" name: "res5a_branch2b" type: "Convolution" convolution_param { num_output: 512 kernel_size: 3 dilation: 2 pad: 2 stride: 1 bias_term: false } }

[naibaf7]

@KeyKy What engine, device and Caffe are you using?

[KeyKy]

@naibaf7 sorry, is my counting mistake.

[thesby]

Is the dilated convolution supported now on latest caffe1.0 and latest cuDNN?

[lizmcquarrie]

SpatialDialatedConvolution is in the R6 branch of cudnn: https://github.com/soumith/cudnn.torch/tree/R6