Can Qwen3.8-Flash-Next run on Mac Studio M5 Max 128GB?
What this means
Qwen3.8-Flash-Next fits on the Mac Studio M5 Max · 128GB at IQ4_XS. We estimate it uses 107.9GB of the conservative 120GB working budget.
Estimated decode speed is 68.3–95.6 tokens/s. A roughly 300-word answer may take around 5 seconds.
See how fast it feels
Using the midpoint of our 68.3–95.6 tokens/s estimate for this demo.
Where the memory goes
| Component | Detail | GB |
|---|---|---|
| Model weights | IQ4_XS GGUF (93.7 GB) + mmap overhead | 98.4 |
| KV cache | 4K context window | 8.8 |
| Runtime | macOS inference app + compute buffers | 0.8 |
| Total needed | at IQ4_XS, 4K context | 107.9 |
| Working budget | 128 GB unified memory − conservative macOS reserve | 120 |
| Headroom | remaining inside the working budget | 12.1 |
Pick your quant
| Quant | Download | Memory | Estimated speed | Verdict |
|---|---|---|---|---|
| IQ1_S | 72.5 GB | 85.7 GB | ~88.2–123.5 tok/s | ✓ Runs great |
| IQ4_XS ★ | 93.7 GB | 107.9 GB | ~68.3–95.6 tok/s | ✓ Runs great |
Get it running on this Mac
This Mac has enough memory, but the tracked IQ4_XS ternary file is not supported by the current point-and-click apps. For a first local chat, use Bonsai 27B 1-bit in Locally AI. Do not download PQ2_0; the publisher marks it unsupported.
The advanced path is complete below, but it is not required for ordinary local AI.
Advanced publisher setup (Terminal)
Install Apple's command-line tools if macOS asks, then run:
git clone https://github.com/PrismML-Eng/Bonsai-demo.git
cd Bonsai-demo
BONSAI_OPENWEBUI=0 BONSAI_SKIP_MLX=1 BONSAI_FAMILY=undefined BONSAI_MODEL=undefined ./setup.sh
BONSAI_FAMILY=undefined BONSAI_MODEL=undefined BONSAI_CTX=4096 ./scripts/start_llama_server.shWhen the server says it is ready, open http://localhost:8080. Start with 4K context. This route uses the publisher's Prism runtime, not Jan or LM Studio.
Other models on this Mac
Qwen3.8-Flash-Next on other Mac Studio M5 Max configurations
FAQ
Can the Mac Studio M5 Max · 128GB run Qwen3.8-Flash-Next?
Yes at IQ4_XS. We estimate about 107.9GB of working memory and 68.3–95.6 tokens/s at 4K context.
Which Qwen3.8-Flash-Next quant should I use on this Mac?
IQ4_XS. It is a 93.7GB download and leaves about 12.1GB inside our conservative working budget.
Which app should I use for Qwen3.8-Flash-Next on this Mac?
Current beginner Mac apps do not load this exact file. Use Bonsai 27B 1-bit in Locally AI instead, or open the advanced publisher instructions on this page.
Are these speeds measured on a Mac Studio M5 Max?
No. The range is a formula estimate based on memory bandwidth, model size, active parameters, cooling, and a 4K context. The app, backend, thermals, and prompt can change real performance.