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Try a 125B model on a 96 GB GPU

Serve Qwen3.8-Flash-Next, a 125B mixture-of-experts model, on a single 96 GB GPU and chat with it from your laptop - about seven minutes from nothing to answers.

Qwen3.8-Flash-Next has 125 billion parameters, but only about 6 billion are active for each token, plus a 51B n-gram table that can live in host RAM. That makes it usable on one 96 GB GPU. The qwen3.8-flash-next recipe has the settings that make it fit.

You need: Colab Pro+ with a G4, or Hugging Face credits for an rtx-pro-6000. Cost: about 9 compute units or $2.75 per hour.

1. Preview

hi compute serve qwen3.8-flash-next --on colab --name qwen --max 1h --dry-run
Recipe qwen3.8-flash-next, tested on Colab G4, 2026-09-27: ~84 tokens/s through hi compute serve (~103 in colab-runner), 62.9 GB VRAM at 131k context, ready in ~7 min.
Start colab/qwen on G4 (~8.9 units/h), stopping after 1h at 15:10.
Would run: colab new -s qwen --gpu G4
Would serve unsloth/Qwen3.8-Flash-Next-GGUF:UD-Q3_K_XL on port 8000.

2. Serve

hi compute serve qwen3.8-flash-next --on colab --name qwen --max 1h

The machine builds llama.cpp and downloads the 90 GB model at the same time:

Step Time on a Colab G4
Start the machine ~20 s
Build llama.cpp (in parallel) ~2 min
Download 90 GB from the Hub ~4.5 min
Load the model < 1 min
Total ~7 min

When it is ready, hi tunnels the API to your laptop:

OpenAI-compatible API: http://127.0.0.1:8080/v1   model: qwen3.8-flash-next
Forwarding http://127.0.0.1:8080 to qwen port 8000. Press Ctrl+C to close.

Leave this terminal open and use another one.

3. Chat with it

curl -s http://127.0.0.1:8080/v1/chat/completions \
  -H 'Content-Type: application/json' \
  -d '{"model": "qwen3.8-flash-next", "max_tokens": 2000,
       "messages": [{"role": "user", "content": "What is a compute unit on Google Colab?"}]}' \
  | python3 -c 'import json, sys; print(json.load(sys.stdin)["choices"][0]["message"]["content"])'

It generates about 84 tokens per second through hi. It thinks before answering; the thinking arrives separately in reasoning_content, so give it a generous max_tokens.

4. Stop

Press Ctrl+C in the serving terminal and answer y to stop the machine, or from anywhere:

hi compute stop qwen

Why the recipe works

The recipe passes these llama-server flags:

  • -ot 'per_layer_token_embd\.weight=CPU' keeps the 28.8 GB n-gram table in host RAM and everything else on the GPU, using about 63 GB of the 96 GB of VRAM at a 131k context.
  • --lazy-mode off loads that table fully into RAM instead of streaming it from disk, which is slow on Colab’s network storage.

On Hugging Face

The same recipe runs on an rtx-pro-6000, which also has 96 GB:

hi compute serve qwen3.8-flash-next --on hf --name qwen --max 1h

There, llama-server downloads the model itself, and hi prints an HTTPS URL instead of tunnelling; use your Hugging Face token as the API key. See Serve a model.

The recipe was measured on a Colab G4. The Hugging Face flow was tested with a smaller model; expect similar speed on the same GPU.