GoKawiilReverse-engineered fix restores lost DRAM bandwidth on Apple's M3 Neural Engine
A developer profiling Apple's M3 Neural Engine found an RTL performance bug that cuts DRAM weight-streaming speed from a normal 45-60 GB/s down to just 17-19 GB/s whenever a model's total weight size lands on an exact multiple of 1 MiB, affecting 7 of the 15 models in the ANEMLL project. By rerouting around the flawed speculative prefetch path in the kernel's DMA engine, the developer restored full throughput, more than doubling token generation speeds for Llama 3.2 1B and Qwen3-8B.