Qwen3.8 27B
2× AMD RX 6800 XT 16GB · llama.cpp
- generation:
- 45.0 tokens/s
- prompt processing (prefill):
- 450.0 tokens/s
- quant:
- Q6_K (GGUF)
- kv:
- Q8_0
User reports Qwen3.8 27B at 45 t/s generation and 450 t/s prompt processing on dual RX 6800 XT GPUs under Linux with ROCm. Setup is llama.cpp with Q6_K weights and Q8_0 KV cache, using MTP speculative decoding and tensor parallelism across two gfx1030 cards. User compares Windows 11 Vulkan results: 35 t/s TG and 180 t/s PP with MTP, 20 t/s TG and 360 t/s PP without MTP, and 15 t/s TG and 350 t/s PP with tensor parallelism and no MTP. User notes a Windows Vulkan bug that halves prompt processing and asks about performance ceilings and other engines.