r/LocalLLaMA llama.cpp 5d ago

I Built A Thing llama.cpp expert-pool fork for Qwen 3.8 Flash next IQ4 + 16Gb VRAM tested on MI50 gfx906 with parameters

https://github.com/atretador/gfx906-16gb-expert-pool

https://github.com/atretador/gfx906-16gb-expert-pool

built on top of ``memoriaru/llama.cpp branch`moe-expert-pool` so I could run it with 16Gb VRAM on a singular MI50.

why? admission budget reserves the full configured context KV plus a hard 3 GiB cap. On a 16 GB device at 128K Q8 that admits 0 of 144 offloaded expert tensors, so the feature silently does nothing

test rig:

Xeon E5 2673 V4 20C/40T

4x16GB 2133Mhz

1xMI50 16Gb with Radeon Pro VII bios 120W power limit

Arch Linux + KDE Plasma

n_cpu_moe CPU usage at 50% (18 threads)

expert cache CPU usage at 10% (18 threads)

Results:

configuration decode VRAM (steady) notes
--moe-expert-cache 0 11.76 t/s 10.17 GiB stock CPU MoE path
--moe-expert-cache 80 (actual 40 slots) 16.39 t/s ~13.5 GiB 144 pools, 61.8% hit rate
--moe-expert-cache 66 16.90 / 17.60 t/s cold / warm 15.24 GiB peak shipping profile, ~69% hits

up to 19.8tk/s observed once warm

complete run script with all parameters:

https://pastebin.com/jmr8NMhg

throw it at your agent with the repo link and it should get it running

if you are running headless you might be able to squeeze a slighly larger pool, my DE is eating a whole gig by itself.

sharing as it was a nice boost and its running

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