[greato]

In neural translation seq2seq, using while_loop in the decoder RNN saves a lot of GPU time because it can quit early when a sentence ends.

[fdrdrive]

I see - you're talking about a use case like this: https://github.com/google/seq2seq/blob/4c3582741f846a19195ac...

I agree that you have to use a tf.while_loop in those cases. But then tf.scan isn't an option, so I don't understand what you mean by 'quit early' or 'saves time'.

When tf.scan is possible, i.e. when you have an input sequence you want to scan over, it is a perfectly good option.

[greato]

Unless you want to execute the structure on multiple GPUs.

[fdrdrive]

I don't understand how that's related.