Gemma 4 31B Quantization Comparison: Best FP8, NVFP4, and INT4 Models
Summary
An evaluation of various quantized versions of the Gemma 4 31B large language model was conducted to assess their impact on accuracy, inference speed, token efficiency, and memory consumption. The study compared the original google/gemma-4-31B-it model (62.6 GB) against several quantized variants, including NVFP4, INT4, and FP8 versions from providers like RedHatAI, NVIDIA, cyankiwi, LilaRest, and Intel, with sizes ranging from 19.2 GB to 33.3 GB. All models were served using vLLM 0.19 on a B200 GPU for evaluation, with latency measured on an RTX Pro 6000. Key findings indicate that while quantization significantly reduces model size, variants with quantized attention layers, such as Intel/gemma-4-31B-it-int4-AutoRound and RedHatAI/gemma-4-31B-it-NVFP4, showed a slight degradation in accuracy, particularly on MMLU-Pro. Token efficiency remained largely stable across most quantized models, with Intel's smallest variant generating approximately 1.1x more tokens.
Key takeaway
For NLP engineers deploying Gemma 4 31B, you should prioritize quantized versions like NVIDIA's NVFP4 or Red Hat AI's FP8 variants to significantly reduce memory footprint and improve inference speed. Be aware that models with quantized attention layers may exhibit a minor accuracy drop, especially on benchmarks like MMLU-Pro, but overall performance remains close to the original BF16 model. Choose a variant based on your specific hardware constraints and acceptable accuracy trade-offs.
Key insights
Quantization effectively compresses Gemma 4 31B, reducing memory and improving speed with minimal accuracy loss.
Principles
- Quantizing attention layers can slightly degrade accuracy.
- Quantization has little impact on token efficiency.
Method
Evaluated Gemma 4 31B quantized variants (NVFP4, INT4, FP8) for accuracy, efficiency, and memory using vLLM 0.19 on a B200 GPU.
In practice
- Consider NVFP4 or FP8 for strong performance.
- Quantized models below 30 GB typically quantize attention layers.
Topics
- Gemma 4 31B
- LLM Quantization
- FP8 Quantization
- NVFP4 Quantization
- INT4 Quantization
Best for: NLP Engineer, Machine Learning Engineer, AI Engineer, AI Scientist
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Editorial summary, takeaway, and curation by AIssential. Original article published by The Kaitchup – AI on a Budget.