gpt-oss 21B (3.6B active)
on AMD Strix Halo 128GB · llama.cpp b6451 / 360d6533 / Windows Vulkan
Summary
User reports gpt-oss 20B at 70.3 t/s generation and 1828.8 t/s prompt processing on an AMD Strix Halo 128GB machine.
Setup is llama.cpp build b6451 with the Vulkan backend, MXFP4 GGUF, flash attention enabled and -ngl 999 on a single Radeon 8060S iGPU.
The figures are separate synthetic PP512 and TG128 phases, not one 512-in/128-out request; a prompt sweep from PP512 to PP32768 fell from 1777.47 to 591.93 t/s, and PP65536 and PP131072 were interrupted with no completed rows.