Gemma 4 31B

User benchmarks Gemma 4 31B on an RX 7900 XTX, reporting 30.13 t/s generation and 422.27 t/s prompt processing with ROCm. Setup is llama.cpp on Windows 10 with the UD-Q4_K_XL GGUF, flash attention, 32K context, all layers on GPU, and a Q4_0 KV cache. Vulkan single-GPU gave 24.81 t/s generation and 117.29 t/s prompt, while Vulkan multi-GPU with an added RTX 3080 gave 26.18 t/s generation and 74.69 t/s prompt. User notes ROCm started at maximum generation speed and declined with context, whereas Vulkan briefly sped up before declining.