Can Gemma 4 31B run on Mac Studio M1 Ultra 64GB?

YES — Tight Fit

S86Excellent

Estimated from fit model

Gemma 4 31B needs ~41.2 GB VRAM. Mac Studio M1 Ultra 64GB has 46.1 GB. With Q4_K_M quantization, expect ~19 tok/s.

Runtime: llama.cppCapacity: TightBandwidth: 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) — 41.2 GB, 18.7 tok/s, Tight fit

41.2 GB required46.1 GB available

89% VRAM used

Fit status

Tight fit

Decode

18.7 tok/s

TTFT

10355 ms

Safe context

21K

Memory

41.2 GB / 46.1 GB

Memory breakdown

Weights18.7 GB

KV Cache14.6 GB

Runtime0.9 GB

Headroom6.9 GB

See how fast it feels

See how fast it feelsGemma 4 31B on Mac Studio M1 Ultra 64GB
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: 18.7 tok/s decode · 10.4s TTFT (warm) · 47 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	18.7 tok/s	5648 ms	21K
Coding	S	Tight fit	18.7 tok/s	10355 ms	21K
Agentic Coding	F	Too heavy	14.1 tok/s	20020 ms	21K
Reasoning	S	Tight fit	18.7 tok/s	12238 ms	21K
RAG	F	Too heavy	14.1 tok/s	25025 ms	21K

Quantization options

How Gemma 4 31B (30.700000762939453B params) fits at each quantization level on Mac Studio M1 Ultra 64GB (46.1 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	12.0 GB	Low	A81
Q3_K_S	3	15.0 GB	Low	A82
NVFP4	4	17.2 GB	Medium	A82
Q4_K_M	4	18.7 GB	Medium	A83
Q5_K_M	5	22.1 GB	High	A84
Q6_K	6	25.2 GB	High	S85
Q8_0Best for your GPU	8	32.8 GB	Very High	A85
F16	16	62.9 GB	Maximum	F0

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 M1 Ultra 64GB can run

Model	Params	Grade	Decode
Qwen 3.6 35B A3B	35B	S	55.9 tok/s
Qwen 3.5 35B A3B	35B	S	60.8 tok/s
Qwen 3 32B	32B	S	24.5 tok/s

Frequently asked questions

Can Mac Studio M1 Ultra 64GB run Gemma 4 31B?

Yes, Mac Studio M1 Ultra 64GB can run Gemma 4 31B with a S grade (Tight fit). Expected decode speed: 18.7 tok/s.

How much VRAM does Gemma 4 31B need?

Gemma 4 31B (30.700000762939453B parameters) requires approximately 41.2 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 M1 Ultra 64GB?

On Mac Studio M1 Ultra 64GB, Gemma 4 31B achieves approximately 18.7 tokens per second decode speed with a time-to-first-token of 10355ms using Q4_K_M quantization.

Can Mac Studio M1 Ultra 64GB run Gemma 4 31B for coding?

For coding workloads, Gemma 4 31B on Mac Studio M1 Ultra 64GB receives a S grade with 18.7 tok/s and 21K context.

What context window can Gemma 4 31B use on Mac Studio M1 Ultra 64GB?

On Mac Studio M1 Ultra 64GB, Gemma 4 31B can safely use up to 21K tokens of context. The model's official context limit is 256K, but available memory constrains the safe maximum.

Is unified memory on Mac Studio M1 Ultra 64GB as fast as VRAM for Gemma 4 31B?

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.

See all results for Mac Studio M1 Ultra 64GB See all hardware for Gemma 4 31B

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