Non-Determinism in TensorFlow ResNets
This highlights a critical issue for deep learning practitioners, as it reveals that much of the variation in model evaluation stems from GPU randomness, calling for more robust evaluation strategies.
The study found that GPU non-determinism, not weight initialization or minibatch sequences, dominates stochasticity in training TensorFlow ResNets for image classification, with test accuracy standard deviation at 0.02 with fixed seeds versus 0.027 with different seeds, accounting for nearly 74% of variation.
We show that the stochasticity in training ResNets for image classification on GPUs in TensorFlow is dominated by the non-determinism from GPUs, rather than by the initialisation of the weights and biases of the network or by the sequence of minibatches given. The standard deviation of test set accuracy is 0.02 with fixed seeds, compared to 0.027 with different seeds---nearly 74\% of the standard deviation of a ResNet model is non-deterministic. For test set loss the ratio of standard deviations is more than 80\%. These results call for more robust evaluation strategies of deep learning models, as a significant amount of the variation in results across runs can arise simply from GPU randomness.