MiniCPM5-2B-DSpark GGUF

GGUF of openbmb/MiniCPM5-2B-DSpark for llama.cpp speculative decoding.

This is the draft model only. Pair it with a MiniCPM5-2B target GGUF (official openbmb/MiniCPM5-2B-GGUF or your own convert). It will not run as a standalone chat model.

A note from me

Same deal as my other uploads: I convert these to run on my own box, then share them. OpenBMB shipped the DSpark weights as BF16 safetensors. There was no GGUF on the official page, so I built these.

Please report anything you find. Bad accept length, crashes, wrong metadata, a better flag for a particular card — open a discussion here or reach me at @ItsmeAjayKV.

Files

Tokenizer came from openbmb/MiniCPM5-2B via --target-model-dir during convert. Vocab size is 130560. Block size is 7. Arch in the GGUF is dflash (DSpark = DFlash + Markov head).

Download (CLI)

hf download hf://aj9o9/MiniCPM5-2B-DSpark-GGUF/MiniCPM5-2B-DSpark-F16.gguf

Or the smaller one:

hf download hf://aj9o9/MiniCPM5-2B-DSpark-GGUF/MiniCPM5-2B-DSpark-Q8_0.gguf

How I run it

Needs a recent llama.cpp with draft-dspark. Pair with the target. KV cache as Q8_0 (-ctk / -ctv) on my box:

llama-server \
  --model MiniCPM5-2B-F16.gguf \
  -md MiniCPM5-2B-DSpark-F16.gguf \
  --spec-type draft-dspark \
  --spec-draft-n-max 7 \
  --host 127.0.0.1 --port 8080 \
  -ngl 999 -ngld 999 -fa on -np 1 -t 12 --jinja \
  -ctk q8_0 -ctv q8_0

Local -m / -md is the reliable path. Hub download flags vary by llama.cpp build.

Official sampling from the MiniCPM5-2B card: temperature=1.0, top_p=0.95. For checking draft accept length, greedy / t=0 is cleaner.

Numbers I actually measured

Same box, same target (MiniCPM5-2B-F16.gguf), same llama.cpp, Q8_0 KV. llama-benchy, pp2048 + tg256 at several depths. Not MTP — MiniCPM5-2B has no MTP heads. Spec run is DSpark (--spec-type draft-dspark, n-max 7).

Baseline (no speculative)

With DSpark (n-max 7)

Read it like this:

• At 8k depth, DSpark is the point — ~110 → ~182 tg t/s on a 3090.
• PP is a bit slower with the draft loaded (expected; more weight traffic).
• Speedup shrinks as depth grows, but TG still beats baseline out to 64k in this run.
• Extra VRAM is roughly the draft (~0.6G F16) plus overhead → ~8.3G → ~10.1G.

A note on accept length

Official DSpark card reports aggregate accept length around ~5.5 at T=0 and ~4.1 at T=1.0, on in-distribution prompts.

The draft was trained with max sequence length 12,288. At long context (32k / 64k+) I have seen accept length collapse toward ~1.6. That is not a quant bug — you are outside what the draft saw. Keep --depth / context in the training range if you care about the speedup. The TG table above still shows a win at 64k on this box; accept length and wall-clock speedup are related but not the same number.

Convert recipe I used

# draft BF16 from OpenBMB + tokenizer from target MiniCPM5-2B
python convert_hf_to_gguf.py MiniCPM5-2B-DSpark \
  --target-model-dir MiniCPM5-2B \
  --outtype f16 \
  --outfile MiniCPM5-2B-DSpark-F16.gguf

llama-quantize MiniCPM5-2B-DSpark-F16.gguf MiniCPM5-2B-DSpark-Q8_0.gguf Q8_0

Draft config.json architecture is Qwen3DSparkModel even though the target is LlamaForCausalLM. That is how OpenBMB shipped it; llama.cpp maps it.

Hardware this was made on

About the draft

• ~324M params, 5 layers, block size 7
• Target hidden layers used: [1, 10, 20, 30, 39] (GGUF stores extract indices as [2, 11, 21, 31, 40])
• Trained for exact pairing with MiniCPM5-2B

See the original card for training details and their acceptance table: openbmb/MiniCPM5-2B-DSpark.

Links

• Original DSpark (BF16): openbmb/MiniCPM5-2B-DSpark
• Target model: openbmb/MiniCPM5-2B
• Target GGUF: openbmb/MiniCPM5-2B-GGUF
• Runtime: ggml-org/llama.cpp (docs/speculative.md, draft-dspark)

License

Apache 2.0, same as openbmb/MiniCPM5-2B-DSpark.

Disclaimer

Not affiliated with OpenBMB. Provided as-is. Use the official cards for intended use, safety, and limitations.