Can SmolLM3 3B run on MacBook Pro M3 Pro 18GB?
YES — Runs Great
B58Good○Estimated from fit model
SmolLM3 3B needs ~6.6 GB VRAM. MacBook Pro M3 Pro 18GB has 13.0 GB. With Q4_K_M quantization, expect ~42 tok/s.
Runtime: llama.cppCapacity: RoomyBandwidth: Very lowStack: StandardBottleneck: Memory bandwidth
Operating mode
Choose the run profile you care about
Interactive favors responsiveness, while light API and scale-out lean harder on serving readiness. The fit stays the same, but the recommendation lens changes.
Current mode
Balanced
Balanced for general local use. Keeps the ranking neutral across personal and serving workflows.
Select quantization to explore
Q4_K_M (Medium quality) — 6.6 GB, 42.0 tok/s, Runs well
6.6 GB required13.0 GB available
Memory breakdown
Weights1.8 GB
KV Cache2.0 GB
Runtime0.9 GB
Headroom1.9 GB
See how fast it feels
See how fast it feelsSmolLM3 3B on MacBook Pro M3 Pro 18GB
1st promptCold start — includes initialization
>Solve: If a train travels at 60 mph for 2.5 hours, how far does it go?
Let me work through this step by step.
Given information:
- Speed = 60 mph (miles per hour)
- Time = 2.5 hours
Formula: Distance = Speed x Time
Calculation:
Distance = 60 mph x 2.5 h
= 150 miles
The train travels 150 miles.
Double-check: at 60 mph the train covers 60 miles each hour. In half an hour it covers 30 miles. So in 2.5 hours: 60 + 60 + 30 = 150 miles. Confirmed.
2nd promptWarm — model ready, no init overhead
>What if the train stops for 20 minutes halfway?
The stop doesn't change the total distance covered while moving, but it affects total trip time.
Breakdown:
- First half: 1.25 hours at 60 mph = 75 miles
- Stop: 20 minutes (no distance)
- Second half: 1.25 hours at 60 mph = 75 miles
Total distance: 150 miles (same)
Total time: 2.5 h + 0.33 h = 2.83 hours
Average speed: 150 / 2.83 = 53 mph
The distance stays the same but average speed drops to 53 mph because of the stop.
Estimated: 42.0 tok/s decode · 4.6s TTFT (warm) · 105 tok/s prefill
What limits this setup
This setup is broadly balanced for this model.
Shared-memory contention still exists
The OS, browser, and inference runtime all compete for the same physical memory pool, so real-world headroom is less forgiving than raw capacity suggests.
Best improvement path
Performance by workload
| Workload | Grade | Fit | Decode | TTFT | Context |
|---|
| Chat | B | Runs well | 42.0 tok/s | 2514 ms | 68K |
| Coding | B | Runs well | 42.0 tok/s | 4610 ms | 68K |
| Agentic Coding | B | Runs well | 42.0 tok/s | 6705 ms | 68K |
| Reasoning | B | Runs well | 42.0 tok/s | 5448 ms | 68K |
| RAG | B | Runs well | 42.0 tok/s | 8381 ms | 68K |
Quantization options
How SmolLM3 3B (3B params) fits at each quantization level on MacBook Pro M3 Pro 18GB (13.0 GB usable).
| Quant | Bits | VRAM | Quality | Fit |
|---|
Q2_K | 2 | 1.2 GB | Low | C55 |
Q3_K_S | 3 | 1.5 GB | Low | C55 |
NVFP4 | 4 |
Get started
Copy-paste commands to run SmolLM3 3B on your machine.
Run
lms load SmolLM3-3B && lms server start
Frequently asked questions
F16Best for your GPU | 16 | 6.1 GB | Maximum | B60 |
Not always. MacBook Pro M3 Pro 18GB can often fit larger models thanks to unified memory, but a discrete GPU with dedicated high-bandwidth VRAM may still decode faster once the model fits. For this combination, the important distinction is capacity versus sustained throughput.
