How much memory does Gemma 4 31B need?
About 22 GB at Q4_K_M with an 8K context. It runs on a Mac with 32 GB of unified memory or more.
Try other settings in the calculatorMemory by quantization and context
Total memory: weights, KV cache in F16 and about 1 GB of buffers. Under each total, the smallest Mac that can run it with the default GPU memory limit.
| Quantization | 8K context | 32K context | 128K context |
|---|---|---|---|
| Q3_K_M | 18 GB32 GB Mac | 22 GB32 GB Mac | 39 GB64 GB Mac |
| Q4_K_M | 22 GB32 GB Mac | 26 GB48 GB Mac | 42 GB64 GB Mac |
| Q5_K_M | 25 GB48 GB Mac | 29 GB48 GB Mac | 46 GB64 GB Mac |
| Q6_K | 29 GB48 GB Mac | 33 GB48 GB Mac | 49 GB96 GB Mac |
| Q8_0 | 36 GB64 GB Mac | 40 GB64 GB Mac | 57 GB96 GB Mac |
| F16 | 66 GB96 GB Mac | 70 GB96 GB Mac | 86 GB128 GB Mac |
About the model
- Parameters
- 31.27B
- Type
- Dense
- Attention
- sliding window plus full attention
- KV cache, F16
- 2.2 GB at 8K, 22 GB at 128K
- On Hugging Face
- google/gemma-4-31B-it
Some layers only look at the last 1,024 tokens, so their part of the cache stops growing. The full-attention layers still grow with context.
Questions
How much memory does Gemma 4 31B need?
About 22 GB at Q4_K_M with an 8K context: 19 GB of weights, 2.2 GB of KV cache and about 1 GB of buffers. At 32K context it needs about 26 GB.
Can Gemma 4 31B run on a Mac?
Yes. At Q4_K_M with an 8K context it fits on a Mac with 32 GB of unified memory or more, using the default GPU memory limit of about three quarters.
How big is the Gemma 4 31B KV cache?
About 2.2 GB at 8K tokens and 22 GB at 128K tokens with an F16 cache. Its attention design: sliding window plus full attention.
Other models
- Gemma 4 12B
- gpt-oss 20B
- Gemma 4 26B-A4B
- Qwen3.8 27B
- GLM-4.7 Flash
- Qwen3.6 35B-A3B
- gpt-oss 120B
- Mistral Medium 3.5
- Qwen3.8 Flash Next
- DeepSeek V4 Flash
- GLM-5.3
- DeepSeek V4 Pro
- Kimi K3
Data read from Hugging Face on 2026-11-09. These are estimates; benchmarks on this site report measured memory. How the estimate works. Compare all models in the model fit chart.
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