Everything we know about the neural engine
When I was still providing ML consulting services for iOS, I would often get email from people who are confused why their model doesn't appear to be running on the Neural Engine, or why it is so slow when the ANE is supposed to be way faster than the GPU...
It turns out that not every Core ML model can make full use of the ANE. The reason why can be complicated, hence this document tries to answer the most common questions.
The ANE is great for making ML models run really fast on iPhones and iPads. A model that is optimized for the ANE will seriously outperform the CPU and GPU. But the ANE also has limitations. Unfortunately Apple isn't giving third-party developers any guidance on how to optimize their models to take advantage of the ANE. It's mostly a process of trial-and-error to figure out what works and what doesn't.