Mixture-of-experts models only use a slice of their parameters per token, about 3B here. The catch on a phone is that each token can pick different experts at each layer, and the full set won't fit in memory. Loading experts from storage on demand works but stalls generation, while locking the model to a fixed subset of experts speeds it up at the cost of quality[2].
OpenBMB's answer is Lookahead Expert Scheduling. It predicts which experts the next layer is likely to need and preloads them, then computes the already-loaded ones first while fetching the rest. The prediction only guides loading: the model still runs exactly the experts its router chooses, so OpenBMB describes it as lossless[2]. Layer-wise quantisation shrinks what has to be moved, and DSpark speculative decoding adds more speed. OpenBMB credits the package with a 5x speedup on real devices[1].
The 13-plus tokens a second figure is OpenBMB's own, measured on one phone. It has published unedited screen recordings of the 35B model on an iPad M4 and the 1B on an iPhone 17 Pro Max[1].