A Qwen 2.5 500M will get you to ≈45tok/sec on an iPhone 13. Inference speeds are somewhat linearly inversely proportional to model sizes.
Yes, speeds are consistent across frameworks, although (and don't quote me on this), I believe React Native is slightly slower because it interfaces with the C++ engine through a set of bridges.
When I was working with RAG llama.cpp through RN early last year I had pretty acceptable tok/sec results up through 7-8b quantized models (on phones like the S24+ and iPhone 15pro). MLC was definitely higher tok/sec but it is really tough to beat the community support and availability in the gguf ecosystem.
Most of the standard mobile CPU benchmarks (GeekBench, AnTuTu, et al) show a 20-40% performance gain over S23/S24 Ultra. Also, this bucks the trend where most other devices are ranked appropriately (i.e. newer devices perform better).
Thanks for sharing your project.
S25 is an outlier that surprised us too.
I got $10 on S25 climbing back up to the top of the rankings as more data comes in :)