Is unified memory on Mac Studio M3 Ultra 256GB as fast as VRAM for Qwen3-Coder 30B A3B Instruct?

Not always. Mac Studio M3 Ultra 256GB 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.

Can Qwen3-Coder 30B A3B Instruct run on Mac Studio M3 Ultra 256GB?

YES — Runs Great

S90Excellent

Estimated from fit model

Qwen3-Coder 30B A3B Instruct needs ~48.6 GB VRAM. Mac Studio M3 Ultra 256GB has 184.3 GB. With Q4_K_M quantization, expect ~84 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) — 48.6 GB, 84.2 tok/s, Runs well

48.6 GB required184.3 GB available

26% VRAM used

Fit status

Runs well

Decode

84.2 tok/s

TTFT

2299 ms

Safe context

256K

Memory

48.6 GB / 184.3 GB

Memory breakdown

Weights18.6 GB

KV Cache1.5 GB

Runtime0.9 GB

Headroom27.6 GB

See how fast it feels

See how fast it feelsQwen3-Coder 30B A3B Instruct on Mac Studio M3 Ultra 256GB
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: 84.2 tok/s decode · 2.3s TTFT (warm) · 211 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	84.2 tok/s	1254 ms	256K
Coding	S	Runs well	84.2 tok/s	2299 ms	256K
Agentic Coding	S	Runs well	84.2 tok/s	3344 ms	256K
Reasoning	S	Runs well	84.2 tok/s	2717 ms	256K
RAG	S	Runs well	84.2 tok/s	4180 ms	256K

Quantization options

How Qwen3-Coder 30B A3B Instruct (30.5B params) fits at each quantization level on Mac Studio M3 Ultra 256GB (184.3 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	11.9 GB	Low	A80
Q3_K_S	3	14.9 GB	Low	A80
NVFP4	4

Get started

Copy-paste commands to run Qwen3-Coder 30B A3B Instruct on your machine.

Run

ollama run qwen3-coder

Your hardware

More models your Mac Studio M3 Ultra 256GB can run

Model	Params	Grade	Decode	Capabilities
Devstral 2 123B Instruct	123B	S	8.1 tok/s

Frequently asked questions

Can Mac Studio M3 Ultra 256GB run Qwen3-Coder 30B A3B Instruct?

Yes, Mac Studio M3 Ultra 256GB can run Qwen3-Coder 30B A3B Instruct with a S grade (Runs well). Expected decode speed: 84.2 tok/s.

How much VRAM does Qwen3-Coder 30B A3B Instruct need?

Qwen3-Coder 30B A3B Instruct (30.5B parameters) requires approximately 48.6 GB of memory with Q4_K_M quantization.

What is the best quantization for Qwen3-Coder 30B A3B Instruct?

The recommended quantization for Qwen3-Coder 30B A3B Instruct is Q4_K_M, which balances quality and memory efficiency.

What speed will Qwen3-Coder 30B A3B Instruct run at on Mac Studio M3 Ultra 256GB?

On Mac Studio M3 Ultra 256GB, Qwen3-Coder 30B A3B Instruct achieves approximately 84.2 tokens per second decode speed with a time-to-first-token of 2299ms using Q4_K_M quantization.

Can Mac Studio M3 Ultra 256GB run Qwen3-Coder 30B A3B Instruct for coding?

For coding workloads, Qwen3-Coder 30B A3B Instruct on Mac Studio M3 Ultra 256GB receives a S grade with 84.2 tok/s and 256K context.

What context window can Qwen3-Coder 30B A3B Instruct use on Mac Studio M3 Ultra 256GB?

On Mac Studio M3 Ultra 256GB, Qwen3-Coder 30B A3B Instruct can safely use up to 256K tokens of context. The model's official context limit is 256K, but available memory constrains the safe maximum.

See all results for Mac Studio M3 Ultra 256GB See all hardware for Qwen3-Coder 30B A3B Instruct

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