Qwen3.8 125B (6B active) Flash-Next
M5 Ultra 256GB · llama.cpp · 262,144 ctx
- generation:
- 100.2 tokens/s
- prompt processing (prefill):
- 2150.0 tokens/s
- quant:
- IQ4_NL (GGUF)
- kv:
- f16
Reported by the source; GPU count, offloading and concurrent requests can change these figures. Prompt-processing speed is input throughput, not time to first token. Check the full setup before comparing.
User reports Qwen3.8-Flash-Next at 100.2 tok/s on an M5 Ultra Mac Studio with 256GB unified memory. Setup is llama.cpp b11538 with IQ4_NL weights, f16 KV cache, 262K context, and MTP speculative decoding with probabilistic drafting at n-max 5. Without speculation the model decodes at 57.0 tok/s; prompt processing reaches 2150 tok/s with ubatch 4096. The full 262K context fits with about 103 GB of GPU memory free. A second copy of the model loaded by another app caused swapping and dropped speed to 12 tok/s.