For single batch inference of anything remotely LLM you'll hit the memory bound way before FLOPs, so I haven't actually looked at FLOPs much. For raw performance GPU is certainly better. ANE is more energy efficient, but you need larger batches to really benefit.
Maybe cache is the wrong word. This is a limit to how much can be mmap'd for the ANE at once. It's not too hard to hit on M1 if your model is in the GB range. Chunking the model into smaller pieces makes it more likely to "fit", but if it doesn't fit you have to unmap/remap in each forward pass which will be noticeable.
Awesome to hear about ModernBERT! Big fan of your work as well :)
What do you mean by less wide? The main bottleneck for transformers is memory bandwidth. ANE has a much lower ceiling than CPU/GPU (yes, despite unified memory).
Chunking is actually beneficial as long as all the chunks can fit into the ANE’s cache. It speeds up compilation for large network graphs and cached loads are negligible cost. On M1 the cache limit is 3-4GB, but it is higher on M2+.
Not a public follow-up but the iOS 17 speech-to-text model has a clever approach to KV caching that works within the ANE’s constraints (fixed size inputs).
I wrote about it here[0] but the gist is you can have a fixed size cache and slide it in chunks with each inference. Not as efficient as a cache that grows by one each time of course.
I bet these can all run on ANE. I’ve run gpt2-xl 1.5B on ANE [1] and WhisperKit [2] also runs larger models on it.
The smaller ones (1.1B and below) will be usably fast and with quantization I suspect the 3B one will be as well. GPU will still be faster but power for speed is the trade-off currently.
MobileVLM [1] is another recent small multimodal model. They trained their own 1.4B/2.7B LLaMa from scratch using RedPajama and Vicuna instead of leveraging Phi-2.
The papers only have one common benchmark (GQA, MobileVLM scores better) so hard to say how they compare otherwise.