Qwen3.8 27B

on 2× NVIDIA RTX 5070 Ti · llama.cpp · 49,152 ctx

Sep 7, 2026

Throughput

22.3 t/s gen · 1003.9 tokens/s prompt processing (prefill)Prompt processing measures input prefill speed; it does not tell you the time to first token.

Quant

Q4_K_XL (GGUF)

KV cache

System RAM

31 GB

VRAM reported

28 GB

Summary

User reports Qwen3.8-27B at 22.30 t/s generation and 1003.85 t/s prefill on an RTX 5070 Ti Laptop 12GB plus an RTX 5060 Ti 16GB eGPU. Setup is llama.cpp with layer-split across the two cards. Q4_K_XL measures 1003.85/22.30 t/s pp512/tg128, Q5_K_XL 923.21/19.11, and Q6_K 901.18/18.23. MTP speculative decoding raises generation to 32-38 t/s. The context ceiling is 49,152 for Q6_K and 73,728 for Q5_K_XL. The user also notes tensor-split syntax differences and eGPU power interruption.

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