BNNS vs Metal CNN benchmark
This app compares the speed of Apple's two deep learning frameworks: BNNS and Metal Performance Shaders (MPSCNN).
It creates a basic convolutional neural network with 2 convolutional layers, 2 pooling layers, and a fully-connected layer. Then it measures how long it takes to sends the same image 100 times through the network.
To run the app you need Xcode 8 and an iOS 10-compatible device with at least an A8 processor.
See also the blog post.