Why is my GPU slower than CPU when training LSTM/RNN models?

Question

My machine has the following spec:

CPU: Xeon E5-1620 v4

GPU: Titan X (Pascal)

Ubuntu 16.04

Nvidia driver 375.26

CUDA tookit 8.0

Answer 1

Too small batch size. Try to increase.

Results for my GTX1050Ti:

imdb_bidirectional_lstm.py
batch_size      time
32 (default)    252
64              131
96              87
128             66

imdb_lstm.py
batch_size      time
32 (default)    108
64              50
96              34
128             25