Qwen3.8 27B

User reports Qwen3.8 27B at 37 t/s generation and 1069 t/s prompt processing on two Radeon AI PRO R9700 32GB cards in a GMKtec EVO-X2 Strix Halo machine. Setup is llama.cpp with the ROCm build, RCCL enabled via -DGGML_HIP_RCCL=ON, and the UD-Q4_K_XL GGUF. The GPUs connect over NVMe-to-USB4 enclosures and run at PCIe 4.0 x4. Tensor parallelism was slower than a single card under the Vulkan build; the ROCm build restored a decode speedup, and RCCL restored full prompt processing. Single card measured 28 t/s generation and 1070 t/s prompt processing.