Qwen3.8 27B

User benchmarks Qwen3.8-27B at 46.72 t/s decode and 1021.1 t/s prefill at 1999 tokens of context on an unspecified NVIDIA GPU. Setup is llama.cpp with IQ4_KS_KT GGUF weights and q4_0 KV cache, 99 GPU layers, 110000 context size, single request, no speculative decoding. The post presents a context-length sweep from 2K to 107K tokens, with decode falling from 46.72 to 23.37 t/s and prefill from 1021.1 to 624.7 t/s. A second model with MTP enabled reaches 64.97 to 97.63 t/s decode, and a third configuration with KV cache 5_0/4_1 shows a VRAM cliff around 107K context.