Qwen 3.8 Flash-Next is a 180B-parameter mixture-of-experts model (6B active per token). At Q4_K_M it needs about 120.3 GB of memory. The Mac Studio M5 Ultra 512GB has 384 GB usable, so it fits entirely in memory. Expect about 145 tokens/sec (123–166), with the first token after 0.3 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 |
|---|---|---|---|---|---|
| Q2_K | 80.9 GB | Fits | 214 tok/s | 0.3 s | Projected |
| GSQ-RCO-IQ3_S | 83.6 GB | Fits | 207 tok/s | 0.3 s | Projected |
| Q3_K_M | 92.0 GB | Fits | 188 tok/s | 0.3 s | Projected |
| IQ4_XS | 97.7 GB | Fits | 177 tok/s | 0.3 s | Projected |
| UD-Q4_K_XL | 111.3 GB | Fits | 155 tok/s | 0.3 s | Projected |
| Q4_K_M | 119.6 GB | Fits | 145 tok/s | 0.3 s | Projected |
| Q8_0 | 188.3 GB | Fits | 92 tok/s | 0.3 s | Projected |
| FP16 | 354.0 GB | Fits | 49 tok/s | 0.3 s | Projected |
All models on the Mac Studio M5 Ultra 512GB · Qwen 3.8 Flash-Next 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.