Can StarCoder2 15B run on Mac Studio M2 Ultra 64GB?

Q: Is unified memory on Mac Studio M2 Ultra 64GB as fast as VRAM for StarCoder2 15B?

Not always. Mac Studio M2 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.

YES — Runs Great

C50Usable

Estimated from fit model

StarCoder2 15B needs ~19.8 GB VRAM. Mac Studio M2 Ultra 64GB has 46.1 GB. With Q5_K_M quantization, expect ~48 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

Q5_K_M (High quality) — 19.8 GB, 47.8 tok/s, Runs well

19.8 GB required46.1 GB available

43% VRAM used

Fit status

Runs well

Decode

47.8 tok/s

TTFT

4047 ms

Safe context

16K

Memory

19.8 GB / 46.1 GB

Memory breakdown

Weights10.8 GB

KV Cache1.2 GB

Runtime0.9 GB

Headroom6.9 GB

See how fast it feels

See how fast it feelsStarCoder2 15B on Mac Studio M2 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: 47.8 tok/s decode · 4.0s TTFT (warm) · 120 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	C	Runs well	47.8 tok/s	2207 ms	16K
Coding	C	Runs well	47.8 tok/s	4047 ms	16K
Agentic Coding	C	Runs well	47.8 tok/s	5886 ms	16K
Reasoning	C	Runs well	47.8 tok/s	4783 ms	16K
RAG	C	Runs well	47.8 tok/s	7358 ms	16K

Quantization options

How StarCoder2 15B (15B params) fits at each quantization level on Mac Studio M2 Ultra 64GB (46.1 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	5.9 GB	Low	C43
Q3_K_S	3	7.4 GB	Low	C44
NVFP4	4

Get started

Copy-paste commands to run StarCoder2 15B on your machine.

Run

docker run --rm -it ghcr.io/ggerganov/llama.cpp:full \
  --hf-repo "bigcode/starcoder2-15b" \
  --hf-file "starcoder2-15b-Q5_K_M.gguf" \
  -c 4096 -ngl 99

Upgrade options

Hardware that runs StarCoder2 15B well

RTX PRO 5000 Blackwell 48GBBudget pick

1344 GB/s (+544)

Raises estimated decode speed by about 144%.116.4 tok/s decode

Raises estimated decode speed by about 144%.

~$4,999 MSRP

RTX 6000 Ada 48GBBest value

960 GB/s (+160)

Raises estimated decode speed by about 70%.81.2 tok/s decode

Raises estimated decode speed by about 70%.

~$6,800 MSRP

Frequently asked questions

Can Mac Studio M2 Ultra 64GB run StarCoder2 15B?

Yes, Mac Studio M2 Ultra 64GB can run StarCoder2 15B with a C grade (Runs well). Expected decode speed: 47.8 tok/s.

How much VRAM does StarCoder2 15B need?

StarCoder2 15B (15B parameters) requires approximately 19.8 GB of memory with Q5_K_M quantization.

What is the best quantization for StarCoder2 15B?

The recommended quantization for StarCoder2 15B is Q5_K_M, which balances quality and memory efficiency.

What speed will StarCoder2 15B run at on Mac Studio M2 Ultra 64GB?

On Mac Studio M2 Ultra 64GB, StarCoder2 15B achieves approximately 47.8 tokens per second decode speed with a time-to-first-token of 4047ms using Q5_K_M quantization.

Can Mac Studio M2 Ultra 64GB run StarCoder2 15B for coding?

For coding workloads, StarCoder2 15B on Mac Studio M2 Ultra 64GB receives a C grade with 47.8 tok/s and 16K context.

What context window can StarCoder2 15B use on Mac Studio M2 Ultra 64GB?

On Mac Studio M2 Ultra 64GB, StarCoder2 15B can safely use up to 16K tokens of context. The model's official context limit is 16K, but available memory constrains the safe maximum.

Is unified memory on Mac Studio M2 Ultra 64GB as fast as VRAM for StarCoder2 15B?

See all results for Mac Studio M2 Ultra 64GB See all hardware for StarCoder2 15B

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