Granite 3.1 8B needs ~14.6 GB VRAM. Mac Studio M1 Ultra 64GB has 46.1 GB. With Q4_K_M quantization, expect ~112 tok/s.
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
Fit status
Runs well
Decode
111.5 tok/s
TTFT
1737 ms
Safe context
128K
Memory
14.6 GB / 46.1 GB
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.
| Workload | Grade | Fit | Decode | TTFT | Context |
|---|---|---|---|---|---|
| Chat | C | Runs well | 111.5 tok/s | 947 ms | 128K |
| Coding | C | Runs well | 111.5 tok/s | 1737 ms | 128K |
| Agentic Coding | C | Runs well | 111.5 tok/s | 2526 ms | 128K |
| Reasoning | C | Runs well | 111.5 tok/s | 2053 ms | 128K |
| RAG | C | Runs well | 111.5 tok/s | 3158 ms | 128K |
Inference speed
Estimated decode speed (tokens/sec) for Granite 3.1 8B at Q4_K_M across popular GPUs and Apple Silicon, using the fastest local runtime per device. Fastest is RTX 5090 32GB at ~112 tok/s. Speed is memory-bandwidth bound, so cards that fit the whole model in VRAM run far faster than ones that offload to system RAM.
| GPU / Mac | Memory | Quant | Speed (tok/s) | Fits? |
|---|---|---|---|---|
| 32 GB | Q4_K_M | 112.0 | Fits | |
| 24 GB | Q4_K_M | 112.0 | Fits | |
| 16 GB | Q4_K_M | 112.0 | Fits | |
| 24 GB | Q4_K_M | 112.0 | Fits | |
RX 7900 XTX 24GB | 24 GB | Q4_K_M | 112.0 | Fits |
Mac Studio M3 Ultra 256GB | 256 GB | Q4_K_M | 112.0 | Fits |
Mac Studio M2 Ultra 128GB | 128 GB | Q4_K_M | 112.0 | Fits |
Mac Studio M1 Ultra 128GB | 128 GB | Q4_K_M | 111.5 | Fits |
| 12 GB | Q4_K_M | 95.8 | Fits | |
MacBook Pro M4 Max 128GB | 128 GB | Q4_K_M | 87.1 | Fits |
MacBook Pro M4 Max 64GB | 64 GB | Q4_K_M | 87.1 | Fits |
MacBook Pro M3 Max 64GB | 64 GB | Q4_K_M | 60.8 | Fits |
| 12 GB | Q4_K_M | 60.2 | Fits | |
MacBook Pro M1 Max 64GB | 64 GB | Q4_K_M | 55.7 | Fits |
MacBook Pro M4 Pro 48GB | 48 GB | Q4_K_M | 53.3 | Fits |
| 8 GB | Q4_K_M | 32.9 | Offloads |
Estimates for single-stream decoding at Q4_K_M; real tokens/sec varies with prompt length, context, batch size, and runtime build. Prompt processing (prefill) is faster than the decode figures shown here.
How Granite 3.1 8B (8B params) fits at each quantization level on Mac Studio M1 Ultra 64GB (46.1 GB usable).
| Quant | Bits | VRAM | Quality | Fit |
|---|---|---|---|---|
Q2_K | 2 | 3.1 GB | Low | C46 |
Q3_K_S | 3 | 3.9 GB | Low | C46 |
NVFP4 | 4 | 4.5 GB | Medium | C46 |
Q4_K_M | 4 | 4.9 GB | Medium | C46 |
Q5_K_M | 5 | 5.8 GB | High | C47 |
Q6_K | 6 | 6.6 GB | High | C47 |
Q8_0 | 8 | 8.6 GB | Very High | C47 |
F16Best for your GPU | 16 | 16.4 GB | Maximum | C50 |
Copy-paste commands to run Granite 3.1 8B on your machine.
Run
ollama run granite3.1-denseYes, Mac Studio M1 Ultra 64GB can run Granite 3.1 8B with a C grade (Runs well). Expected decode speed: 111.5 tok/s.
Granite 3.1 8B (8B parameters) requires approximately 14.6 GB of memory with Q4_K_M quantization.
The recommended quantization for Granite 3.1 8B is Q4_K_M, which balances quality and memory efficiency.
On Mac Studio M1 Ultra 64GB, Granite 3.1 8B achieves approximately 111.5 tokens per second decode speed with a time-to-first-token of 1737ms using Q4_K_M quantization.
For coding workloads, Granite 3.1 8B on Mac Studio M1 Ultra 64GB receives a C grade with 111.5 tok/s and 128K context.
On Mac Studio M1 Ultra 64GB, Granite 3.1 8B can safely use up to 128K tokens of context. The model's official context limit is 128K, but available memory constrains the safe maximum.
Not always. Mac Studio M1 Ultra 64GB 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.
Paste this snippet into any page to show a live fit card.
<iframe src="https://willitrunai.com/embed/granite-3.1-8b-on-m1-ultra-64gb" width="400" height="180" frameborder="0" style="border:none;border-radius:12px;overflow:hidden;" title="Will It Run AI — fit result"></iframe>
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