Can LongCat Flash Chat run on MacBook Pro M3 Pro 18GB?
NO — Won’t fit
IQ1_S · 4K context · formula estimate
What this means
The checked IQ1_S build needs about 159.8GB, above this Mac's conservative 15GB working budget.
−144.8GB short
above the working budget
159.8GB
needed at IQ1_S
IQ1_S
quant selected
0GB
working headroom
needs 159.8 GBworking budget 15 GB · short 144.8 GB
Where the memory goes
| Component | Detail | GB |
|---|---|---|
| Model weights | IQ1_S GGUF (114 GB) + mmap overhead | 119.7 |
| KV cache | 4K context window | 39.3 |
| Runtime | macOS inference app + compute buffers | 0.8 |
| Total needed | at IQ1_S, 4K context | 159.8 |
| Working budget | 18 GB unified memory − conservative macOS reserve | 15 |
| Headroom | memory shortfall | −144.8 |
Pick your quant
| Quant | Download | Memory | Estimated speed | Verdict |
|---|---|---|---|---|
| IQ1_S ★ | 114 GB | 159.8 GB | — | ✕ Won't fit |
Other models on this Mac
LongCat Flash Chat on other MacBook Pro M3 Pro configurations
FAQ
Can the MacBook Pro M3 Pro · 18GB run LongCat Flash Chat?
Not with the quants currently tracked. The selected IQ1_S build needs about 159.8GB, above the 15GB working budget.
Which LongCat Flash Chat quant should I use on this Mac?
None of the tracked quants fit this configuration safely. Choose a smaller model or a Mac with more unified memory.
Which app should I use for LongCat Flash Chat on this Mac?
Start with LM Studio. This page gives the complete point-and-click walkthrough.
Are these speeds measured on a MacBook Pro M3 Pro?
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.