Can Gemma 4 31B run on Mac Studio M3 Ultra 96GB?

Q: Is unified memory on Mac Studio M3 Ultra 96GB as fast as VRAM for Gemma 4 31B?

Not always. Mac Studio M3 Ultra 96GB 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.

YES — Runs Great

S88Excellent

Estimated from fit model

Gemma 4 31B needs ~44.6 GB VRAM. Mac Studio M3 Ultra 96GB has 69.1 GB. With Q4_K_M quantization, expect ~24 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) — 44.6 GB, 23.7 tok/s, Runs well

44.6 GB required69.1 GB available

65% VRAM used

Fit status

Runs well

Decode

23.7 tok/s

TTFT

8181 ms

Safe context

43K

Memory

44.6 GB / 69.1 GB

Memory breakdown

Weights18.7 GB

KV Cache14.6 GB

Runtime0.9 GB

Headroom10.4 GB

See how fast it feels

See how fast it feelsGemma 4 31B on Mac Studio M3 Ultra 96GB
1st promptCold start — includes initialization
>Write a Python function to sort a list
Here's a Python function that sorts a list using quicksort:

def quicksort(arr):
    if len(arr) <= 1:
        return arr
    pivot = arr[len(arr) // 2]
    left   = [x for x in arr if x < pivot]
    middle = [x for x in arr if x == pivot]
    right  = [x for x in arr if x > pivot]
    return quicksort(left) + middle + quicksort(right)

# Example usage
numbers = [3, 6, 8, 10, 1, 2, 1]
print(quicksort(numbers))  # [1, 1, 2, 3, 6, 8, 10]

The algorithm picks a pivot, partitions the list into smaller, equal, and larger elements, then recursively sorts each partition and concatenates the results.
2nd promptWarm — model ready, no init overhead
>Now add type hints and a docstring
def quicksort(arr: list[int]) -> list[int]:
    """Sort a list using the quicksort algorithm.

    Args:
        arr: List of integers to sort.

    Returns:
        A new sorted list.
    """
    if len(arr) <= 1:
        return arr
    pivot = arr[len(arr) // 2]
    left   = [x for x in arr if x < pivot]
    middle = [x for x in arr if x == pivot]
    right  = [x for x in arr if x > pivot]
    return quicksort(left) + middle + quicksort(right)

Added type hints for the input and return type, plus a Google-style docstring.
Estimated: 23.7 tok/s decode · 8.2s TTFT (warm) · 59 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	S	Runs well	23.7 tok/s	4462 ms	43K
Coding	S	Runs well	23.7 tok/s	8181 ms	43K
Agentic Coding	S	Tight fit	23.7 tok/s	11900 ms	43K
Reasoning	S	Runs well	23.7 tok/s	9668 ms	43K
RAG	S	Tight fit	23.7 tok/s	14874 ms	43K

Quantization options

How Gemma 4 31B (30.700000762939453B params) fits at each quantization level on Mac Studio M3 Ultra 96GB (69.1 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	12.0 GB	Low	A78
Q3_K_S	3	15.0 GB	Low	A79
NVFP4	4

Get started

Copy-paste commands to run Gemma 4 31B on your machine.

Run

ollama run gemma4:31b

Your hardware

More models your Mac Studio M3 Ultra 96GB can run

Model	Params	Grade	Decode	Capabilities
Qwen 3.6 35B A3B	35B	S	70.8 tok/s

Frequently asked questions

Can Mac Studio M3 Ultra 96GB run Gemma 4 31B?

Yes, Mac Studio M3 Ultra 96GB can run Gemma 4 31B with a S grade (Runs well). Expected decode speed: 23.7 tok/s.

How much VRAM does Gemma 4 31B need?

Gemma 4 31B (30.700000762939453B parameters) requires approximately 44.6 GB of memory with Q4_K_M quantization.

What is the best quantization for Gemma 4 31B?

The recommended quantization for Gemma 4 31B is Q4_K_M, which balances quality and memory efficiency.

What speed will Gemma 4 31B run at on Mac Studio M3 Ultra 96GB?

On Mac Studio M3 Ultra 96GB, Gemma 4 31B achieves approximately 23.7 tokens per second decode speed with a time-to-first-token of 8181ms using Q4_K_M quantization.

Can Mac Studio M3 Ultra 96GB run Gemma 4 31B for coding?

For coding workloads, Gemma 4 31B on Mac Studio M3 Ultra 96GB receives a S grade with 23.7 tok/s and 43K context.

What context window can Gemma 4 31B use on Mac Studio M3 Ultra 96GB?

On Mac Studio M3 Ultra 96GB, Gemma 4 31B can safely use up to 43K tokens of context. The model's official context limit is 256K, but available memory constrains the safe maximum.

Is unified memory on Mac Studio M3 Ultra 96GB as fast as VRAM for Gemma 4 31B?

See all results for Mac Studio M3 Ultra 96GB See all hardware for Gemma 4 31B

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