DeepSeek V4.1 Flash 552B (16B active)

User reports DeepSeek V4.1 Flash on an M3 Ultra 512GB with oQ4e and Engram in RAM, reaching 439.4 t/s prefill and 19.7 t/s generation at 64K context with MTP off, and 435.6 t/s prefill and 39.7 t/s generation with MTP on. Setup is oMLX 0.7.0.dev2 with Python code prompts, temperature 1.0, 128 generated tokens, and no prefix cache. One measured run per configuration after warm-up. At 4K context, prefill was 458.0 t/s with MTP off and 452.2 t/s with MTP on, while generation was 20.2 t/s and 32.1 t/s respectively. At 16K, prefill was 459.1 t/s and 454.8 t/s, with generation at 20.0 t/s and 34.7 t/s. At 32K, prefill was 452.2 t/s and 447.7 t/s, with generation at 19.8 t/s and 31.5 t/s. The user also notes experimental MoE Expert SSD Offload support for DeepSeek V4.1, Qwen3.8-Flash-Next, Gemma 4 MoE, and OLMoE, and an M5 prefill speedup from 615.2 to 826.7 t/s at 32K on an M5 Max with Qwen3.8-27B using INT8-activation kernels.