Qwen3.5 122B (10B active)

User reports Qwen3.5-122B-A10B at UD-IQ4_XS decoding at 18.75 tok/s on 2x RTX 4090 with expert offload to a Threadripper TRX50 with 128 GB DDR5 (2 of 4 memory channels populated). Setup is llama.cpp on Windows with q8_0 KV cache; the 122B took 11.91 s per agent tool call against 3.40 s for a 27B, so the author shelved it. The rest of the post covers the 27B as a coding subagent: at 64k per agent, Q8_K_XL ran 3 agents (112 s median wait), Q6_K_XL 5 (168 s) and Q4_K_M 9 (330 s), with aggregate prefill near 1,500 tok/s whatever the slot count. Qwen3.6-35B-A3B decoded at 78 tok/s and Qwen3.8-Flash-Next topped out at 23.7 tok/s with experts in system RAM.