Can Pixtral 12B run on Mac Studio M2 Ultra 128GB?

YES — Runs Great

A70Great

Estimated from fit model

Pixtral 12B needs ~24.5 GB VRAM. Mac Studio M2 Ultra 128GB has 92.2 GB. With Q4_K_M quantization, expect ~68 tok/s.

Runtime: llama.cppCapacity: RoomyBandwidth: HighStack: StandardBottleneck: Balanced

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.

Capabilities:

Select quantization to explore

Q4_K_M (Medium quality) — 24.5 GB, 68.1 tok/s, Runs well

24.5 GB required92.2 GB available

27% VRAM used

Fit status

Runs well

Decode

68.1 tok/s

TTFT

2841 ms

Safe context

131K

Memory

24.5 GB / 92.2 GB

Memory breakdown

Weights7.3 GB

KV Cache2.4 GB

Runtime0.9 GB

Headroom13.8 GB

See how fast it feels

See how fast it feelsPixtral 12B on Mac Studio M2 Ultra 128GB
1st promptCold start — includes initialization
>What is local AI inference?
Local AI inference means running an AI language model directly on your own hardware — your laptop, desktop, or server — instead of sending requests to a remote cloud API.

When you run inference locally the model weights are loaded into your GPU or unified memory. Each token you generate requires reading those weights from memory, so memory bandwidth is the main bottleneck for decode speed.

Key benefits of running locally:
  - Full privacy: your prompts never leave your machine
  - No per-token cost or rate limits
  - Works offline once the model is downloaded
  - Latency depends only on your hardware
2nd promptWarm — model ready, no init overhead
>How much VRAM do I need?
It depends on the model size and quantization level. A rough rule of thumb:

  Model size     Q4 (4-bit)    Q8 (8-bit)    FP16
  7B params      ~4.3 GB       ~7.5 GB       ~14 GB
  13B params     ~7.9 GB       ~13.9 GB      ~26 GB
  70B params     ~42.7 GB      ~74.9 GB      ~140 GB

Most people use 4-bit quantization (Q4_K_M) which gives 90-95% of full quality at a fraction of the memory. A 24 GB GPU can comfortably run most 7B-13B models.
Estimated: 68.1 tok/s decode · 2.8s TTFT (warm) · 170 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	68.1 tok/s	1550 ms	131K
Coding	A	Runs well	68.1 tok/s	2841 ms	131K
Agentic Coding	A	Runs well	68.1 tok/s	4133 ms	131K
Reasoning	A	Runs well	68.1 tok/s	3358 ms	131K
RAG	A	Runs well	68.1 tok/s	5166 ms	131K

Inference speed

Pixtral 12B inference speed — tokens per second by GPU & Mac

Estimated decode speed (tokens/sec) for Pixtral 12B at Q4_K_M across popular GPUs and Apple Silicon, using the fastest local runtime per device. Fastest is RTX 5090 32GB at ~168 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?
RTX 5090 32GB	32 GB	Q4_K_M	168.0	Fits
RTX 4090 24GB	24 GB	Q4_K_M	112.5	Fits
RX 7900 XTX 24GB	24 GB	Q4_K_M	101.5	Fits
RTX 3090 24GB	24 GB	Q4_K_M	96.2	Fits
RTX 4080 Super 16GB	16 GB	Q4_K_M	94.2	Fits
Mac Studio M3 Ultra 256GB	256 GB	Q4_K_M	81.8	Fits
Mac Studio M2 Ultra 128GB	128 GB	Q4_K_M	68.1	Fits
Mac Studio M1 Ultra 128GB	128 GB	Q4_K_M	64.6	Fits
RTX 4070 12GB	12 GB	Q4_K_M	58.3	Offloads
MacBook Pro M4 Max 128GB	128 GB	Q4_K_M	44.5	Fits
MacBook Pro M4 Max 64GB	64 GB	Q4_K_M	44.5	Fits
MacBook Pro M3 Max 64GB	64 GB	Q4_K_M	35.2	Fits
RTX 3060 12GB	12 GB	Q4_K_M	34.2	Offloads
MacBook Pro M1 Max 64GB	64 GB	Q4_K_M	32.3	Fits
MacBook Pro M4 Pro 48GB	48 GB	Q4_K_M	27.2	Fits
RTX 4060 8GB	8 GB	Q4_K_M	9.7	Too big

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.

Quantization options

How Pixtral 12B (12B params) fits at each quantization level on Mac Studio M2 Ultra 128GB (92.2 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	4.7 GB	Low	B63
Q3_K_S	3	5.9 GB	Low	B63
NVFP4	4	6.7 GB	Medium	B63
Q4_K_M	4	7.3 GB	Medium	B63
Q5_K_M	5	8.6 GB	High	B63
Q6_K	6	9.8 GB	High	B63
Q8_0	8	12.8 GB	Very High	B63
F16Best for your GPU	16	24.6 GB	Maximum	B65

Get started

Copy-paste commands to run Pixtral 12B on your machine.

Run

ollama run pixtral

Your hardware

More models your Mac Studio M2 Ultra 128GB can run

Model	Params	Grade	Decode
Devstral 2 123B Instruct	123B	S	6.3 tok/s
Qwen3-Coder 30B A3B Instruct	30.5B	S	70.2 tok/s
Qwen 3.5 27B	27B	S	30.4 tok/s
Qwen 3.6 27B	27B	S	23.1 tok/s
Qwen 3.5 122B A10B	122B	S	28.9 tok/s

Frequently asked questions

Can Mac Studio M2 Ultra 128GB run Pixtral 12B?

Yes, Mac Studio M2 Ultra 128GB can run Pixtral 12B with a A grade (Runs well). Expected decode speed: 68.1 tok/s.

How much VRAM does Pixtral 12B need?

Pixtral 12B (12B parameters) requires approximately 24.5 GB of memory with Q4_K_M quantization.

What is the best quantization for Pixtral 12B?

The recommended quantization for Pixtral 12B is Q4_K_M, which balances quality and memory efficiency.

What speed will Pixtral 12B run at on Mac Studio M2 Ultra 128GB?

On Mac Studio M2 Ultra 128GB, Pixtral 12B achieves approximately 68.1 tokens per second decode speed with a time-to-first-token of 2841ms using Q4_K_M quantization.

Can Mac Studio M2 Ultra 128GB run Pixtral 12B for coding?

For coding workloads, Pixtral 12B on Mac Studio M2 Ultra 128GB receives a A grade with 68.1 tok/s and 131K context.

What context window can Pixtral 12B use on Mac Studio M2 Ultra 128GB?

On Mac Studio M2 Ultra 128GB, Pixtral 12B can safely use up to 131K tokens of context. The model's official context limit is 131K, but available memory constrains the safe maximum.

Is unified memory on Mac Studio M2 Ultra 128GB as fast as VRAM for Pixtral 12B?

Not always. Mac Studio M2 Ultra 128GB 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.

See all results for Mac Studio M2 Ultra 128GB See all hardware for Pixtral 12B

Embed this result▼

Paste this snippet into any page to show a live fit card.

<iframe src="https://willitrunai.com/embed/pixtral-12b-on-m2-ultra-128gb" width="400" height="180" frameborder="0" style="border:none;border-radius:12px;overflow:hidden;" title="Will It Run AI — fit result"></iframe>

Preview: