Can Granite Code 20B run on MacBook Pro M4 Max 48GB?

Q: Is unified memory on MacBook Pro M4 Max 48GB as fast as VRAM for Granite Code 20B?

Not always. MacBook Pro M4 Max 48GB 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

A82Great

Estimated from fit model

Granite Code 20B needs ~21.5 GB VRAM. MacBook Pro M4 Max 48GB has 34.6 GB. With Q4_K_M quantization, expect ~38 tok/s.

Runtime: llama.cppCapacity: RoomyBandwidth: MediumStack: 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) — 21.5 GB, 38.4 tok/s, Runs well

21.5 GB required34.6 GB available

62% VRAM used

Fit status

Runs well

Decode

38.4 tok/s

TTFT

5042 ms

Safe context

Memory

21.5 GB / 34.6 GB

Memory breakdown

Weights12.2 GB

KV Cache3.2 GB

Runtime0.9 GB

Headroom5.2 GB

See how fast it feels

See how fast it feelsGranite Code 20B on MacBook Pro M4 Max 48GB
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: 38.4 tok/s decode · 5.0s TTFT (warm) · 96 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	A	Runs well	38.4 tok/s	2750 ms	8K
Coding	A	Runs well	38.4 tok/s	5042 ms	8K
Agentic Coding	A	Runs well	38.4 tok/s	7334 ms	8K
Reasoning	A	Runs well	38.4 tok/s	5959 ms	8K
RAG	A	Runs well	38.4 tok/s	9167 ms	8K

Quantization options

How Granite Code 20B (20B params) fits at each quantization level on MacBook Pro M4 Max 48GB (34.6 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	7.8 GB	Low	A74
Q3_K_S	3	9.8 GB	Low	A75
NVFP4	4

Get started

Copy-paste commands to run Granite Code 20B on your machine.

Run

ollama run granite-code:20b

Your hardware

More models your MacBook Pro M4 Max 48GB can run

Model	Params	Grade	Decode	Capabilities
Qwen3-Coder 30B A3B Instruct	30.5B	S	52 tok/s
Qwen 3.5 27B	27B	S	36.1 tok/s

Frequently asked questions

Can MacBook Pro M4 Max 48GB run Granite Code 20B?

Yes, MacBook Pro M4 Max 48GB can run Granite Code 20B with a A grade (Runs well). Expected decode speed: 38.4 tok/s.

How much VRAM does Granite Code 20B need?

Granite Code 20B (20B parameters) requires approximately 21.5 GB of memory with Q4_K_M quantization.

What is the best quantization for Granite Code 20B?

The recommended quantization for Granite Code 20B is Q4_K_M, which balances quality and memory efficiency.

What speed will Granite Code 20B run at on MacBook Pro M4 Max 48GB?

On MacBook Pro M4 Max 48GB, Granite Code 20B achieves approximately 38.4 tokens per second decode speed with a time-to-first-token of 5042ms using Q4_K_M quantization.

Can MacBook Pro M4 Max 48GB run Granite Code 20B for coding?

For coding workloads, Granite Code 20B on MacBook Pro M4 Max 48GB receives a A grade with 38.4 tok/s and 8K context.

What context window can Granite Code 20B use on MacBook Pro M4 Max 48GB?

On MacBook Pro M4 Max 48GB, Granite Code 20B can safely use up to 8K tokens of context. The model's official context limit is 8K, but available memory constrains the safe maximum.

Is unified memory on MacBook Pro M4 Max 48GB as fast as VRAM for Granite Code 20B?

See all results for MacBook Pro M4 Max 48GB See all hardware for Granite Code 20B

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