Gemma 4 31B is a 31.27B-parameter model. At Q4_K_M it needs about 19.1 GB of memory. The Mac Studio M5 Ultra 512GB has 384 GB usable, so it fits entirely in memory. Expect about 31 tokens/sec (26–36), with the first token after 0.4 s for a short prompt. This estimate is projected from the hardware specs; no benchmarks exist yet.
| Quantization | File size | Memory | Generation | First token | Source |
|---|---|---|---|---|---|
| Q4_K_M | 18.3 GB | Fits | 31 tok/s | 0.4 s | Projected |
| Q8_0 | 32.6 GB | Fits | 17 tok/s | 0.4 s | Projected |
| FP16 | 61.4 GB | Fits | 9.2 tok/s | 0.4 s | Projected |
All models on the Mac Studio M5 Ultra 512GB · Gemma 4 31B on all hardware
Estimates for a short prompt on a single device. Measured numbers come from community benchmarks (r/LocalLLaMA, localscore.ai and more); others are derived from similar setups or projected from specs. Open source on GitHub.