StableLM 2 12B needs ~23.7 GB but MacBook Pro M3 Pro 18GB only has 13.0 GB. Try a smaller quantization or lighter model.
Operating mode
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
10.7 GB over capacity — needs offload or smaller quantization
Fit status
Too heavy
Decode
5.5 tok/s
TTFT
34891 ms
Safe context
4K
Memory
23.7 GB / 13.0 GB
Offload
50%
Usable shared or unified memory is the main blocker for this model.
Not enough usable memory
The model needs 23.7 GB, but this setup only exposes 13.0 GB of usable shared or unified memory.
Move to a larger memory pool
A larger unified-memory SKU or a discrete high-bandwidth GPU is the cleanest way to make this model practical.
| Workload | Grade | Fit | Decode | TTFT | Context |
|---|---|---|---|---|---|
| Chat | F | Too heavy | 7.8 tok/s | 13608 ms | 4K |
| Coding | F | Too heavy | 5.5 tok/s | 34891 ms | 4K |
| Agentic Coding | F | Too heavy | 5.3 tok/s | 52928 ms | 4K |
| Reasoning | F | Too heavy | 5.5 tok/s | 41235 ms | 4K |
| RAG | F | Too heavy | 5.3 tok/s | 66160 ms | 4K |
How StableLM 2 12B (12B params) fits at each quantization level on MacBook Pro M3 Pro 18GB (13.0 GB usable).
| Quant | Bits | VRAM | Quality | Fit |
|---|---|---|---|---|
Q2_K | 2 | 4.7 GB | Low | C50 |
Q3_K_S | 3 | 5.9 GB | Low | C52 |
NVFP4 | 4 |
Upgrade options
Makes the model fit on the accelerator instead of staying completely out of reach.
Raises estimated decode speed by about 29%.
~$799 MSRP
Makes the model fit on the accelerator instead of staying completely out of reach.
Removes host-memory offload, which is usually the single biggest latency and throughput win.
~$1,099 MSRP
Makes the model fit on the accelerator instead of staying completely out of reach.
Raises estimated decode speed by about 29%.
~$1,099 MSRP
RTX 5090 32GBBiggest leapMakes the model fit on the accelerator instead of staying completely out of reach.
Removes host-memory offload, which is usually the single biggest latency and throughput win.
~$1,999 MSRP
No, StableLM 2 12B requires more memory than MacBook Pro M3 Pro 18GB provides.
StableLM 2 12B (12B parameters) requires approximately 23.7 GB of memory with Q5_K_M quantization.
The recommended quantization for StableLM 2 12B is Q5_K_M, which balances quality and memory efficiency.
On MacBook Pro M3 Pro 18GB, StableLM 2 12B achieves approximately 5.5 tokens per second decode speed with a time-to-first-token of 34891ms using Q5_K_M quantization.
For coding workloads, StableLM 2 12B on MacBook Pro M3 Pro 18GB receives a F grade with 5.5 tok/s and 4K context.
On MacBook Pro M3 Pro 18GB, StableLM 2 12B can safely use up to 4K tokens of context. The model's official context limit is 4K, but available memory constrains the safe maximum.
Paste this snippet into any page to show a live fit card.
<iframe src="https://willitrunai.com/embed/stablelm-2-12b-on-m3-pro-18gb" width="400" height="180" frameborder="0" style="border:none;border-radius:12px;overflow:hidden;" title="Will It Run AI — fit result"></iframe>
Preview:
6.7 GB |
| Medium |
| C52 |
Q4_K_M | 4 | 7.3 GB | Medium | C52 |
Q5_K_M | 5 | 8.6 GB | High | C51 |
Q6_KBest for your GPU | 6 | 9.8 GB | High | C51 |
Q8_0 | 8 | 12.8 GB | Very High | F0 |
F16 | 16 | 24.6 GB | Maximum | F0 |
Move to a larger memory pool. A larger unified-memory SKU or a discrete high-bandwidth GPU is the cleanest way to make this model practical.
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.
