dkhokhlov/whisper-small-hqq-4bit

HQQ 4-bit Whisper-Small

Model card source for dkhokhlov/whisper-small-hqq-4bit.

Related models

• dkhokhlov/whisper-tiny-hqq-4bit — HQQ 4-bit, whisper-tiny (CPU eval)
• dkhokhlov/whisper-base-hqq-4bit — HQQ 4-bit, whisper-base (CPU eval)
• Source model: openai/whisper-small (fp32)
• Benchmark + code: dkhokhlov/whisper-cascade

Summary

openai/whisper-small quantized with HQQ 4-bit grouped quantization. Resident weight RAM (fp16 compute, the deployment mode) is 267.59 MB, 44.6% smaller than the unquantized fp16 model (483.47 MB). fp16 compute is WER-neutral; the published WER benchmark uses fp32 compute for cross-model comparability. The config is the same mixed-precision setting tuned on whisper-tiny (whole encoder stack + fc1 at 8-bit, rest 4-bit), applied to small without a separate sweep (see the repo README).

This is the first model in the set evaluated on a GPU for speed. whisper-tiny and whisper-base were quantized and evaluated on CPU; whisper-small (241.7 M parameters, 12+12 layers) was quantized and evaluated on an NVIDIA A10 GPU (ASR_DEVICE=cuda). WER is host-independent; only runtime is host-specific. The saved qmodel.pt is device-independent and loads on CPU or GPU.

English (fleurs en_us, n=100) WER is 0.0636 vs 0.0660 fp32 (-3.6%), within n=100 noise. HQQ is within 5% relative of fp32 on every tested config (5 fleurs + 4 talkbank). whisper-small beats whisper-base on every config.

Results

English (fleurs en_us, n=100, fp32 compute):

Metric	unquantized fp32	HQQ 4-bit	Delta %
WER	0.0660	0.0636	-3.6%
Resident RAM (fp16)	483.47 MB	267.59 MB	-44.6%
Samples succeeded	100 / 100	100 / 100	-

HQQ is within 5% relative of fp32 on every tested config. The full multilingual and telephone WER tables, the cross-reference against whisper-tiny/whisper-base, and the size-by-component breakdown are in the repo README.

Load and use

The model auto-detects the spoken language and transcribes (multilingual Whisper behavior). Pass language to force a language when it is known.

import hqq_asr
pipe = hqq_asr.build_pipeline("dkhokhlov/whisper-small-hqq-4bit", quant="hqq")
text = pipe({"array": audio, "sampling_rate": 16000})["text"]                       # auto-detect
text = pipe({"array": audio, "sampling_rate": 16000},
             generate_kwargs={"language": "spanish", "task": "transcribe"})["text"]   # force

Command line (this repository, GPU venv):

ASR_DEVICE=cuda make asr MODEL_ASR=dkhokhlov/whisper-small-hqq-4bit QUANT=hqq AUDIO=clip.wav

Reproduce

# 1. Create the CUDA venv (A10), then quantize locally (writes whisper-small-hqq-4bit/).
make gpu-venv
ASR_DEVICE=cuda MODEL_ASR=openai/whisper-small HQQ_OUT=whisper-small-hqq-4bit \
  .venv-gpu/bin/python quantize.py

# 2. Measure baseline WER (fp32) on the A10.
ASR_DEVICE=cuda EVAL_LIMIT=100 MODEL_ASR=openai/whisper-small EVAL_CONFIG=en_us \
  EVAL_OUT=eval_small_baseline.json .venv-gpu/bin/python eval_wer.py

# 3. Measure HQQ WER.
ASR_DEVICE=cuda EVAL_LIMIT=100 QUANT=hqq MODEL_ASR=./whisper-small-hqq-4bit EVAL_CONFIG=en_us \
  EVAL_OUT=eval_small_hqq.json .venv-gpu/bin/python eval_wer.py

# 4. Telephone benchmark (talkbank segment split).
ASR_DEVICE=cuda EVAL_DATASET=diabolocom/talkbank_4_stt EVAL_CONFIG=en EVAL_SPLIT=segment EVAL_LIMIT=100 \
  MODEL_ASR=openai/whisper-small EVAL_OUT=small_talkbank_en_fp32.json .venv-gpu/bin/python eval_wer.py

# 5. Publish (needs a Hugging Face write token).
PUSH=1 ASR_DEVICE=cuda HQQ_REPO=dkhokhlov/whisper-small-hqq-4bit MODEL_ASR=openai/whisper-small \
  HQQ_OUT=whisper-small-hqq-4bit HQQ_REPORT=hqq_report_small.md .venv-gpu/bin/python quantize.py

License

MIT. Derived from openai/whisper-small (Apache-2.0) and HQQ. The quantized weights inherit the openai/whisper license terms.

Citation

See the repo README for the BibTeX entry.

Full details

Quantization config, config-sweep ablation, safetensors format, the full WER tables (multilingual fleurs, talkbank telephone, cross-reference), and the resident-RAM-by-component breakdown are in the repo README. Per-config WER evidence JSONs are committed under eval_multilingual/ (prefix small_) and eval_telephone/ (prefix small_) in dkhokhlov/whisper-cascade.