Is unified memory on Mac Studio M2 Ultra 128GB as fast as VRAM for DeepSeek R1 Distill 70B?

Not always. Mac Studio M2 Ultra 128GB 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 DeepSeek R1 Distill 70B run on Mac Studio M2 Ultra 128GB?

YES — Runs Great

A76Great

Estimated from fit model

DeepSeek R1 Distill 70B needs ~62.3 GB VRAM. Mac Studio M2 Ultra 128GB has 92.2 GB. With Q4_K_M quantization, expect ~11 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) — 62.3 GB, 11.8 tok/s, Runs well

62.3 GB required92.2 GB available

68% VRAM used

Fit status

Runs well

Decode

11.8 tok/s

TTFT

16383 ms

Safe context

114K

Memory

62.3 GB / 92.2 GB

Memory breakdown

Weights42.7 GB

KV Cache4.9 GB

Runtime0.9 GB

Headroom13.8 GB

See how fast it feels

See how fast it feelsDeepSeek R1 Distill 70B on Mac Studio M2 Ultra 128GB
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: 11.8 tok/s decode · 16.4s TTFT (warm) · 30 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	10.9 tok/s	9718 ms	114K
Coding	A	Runs well	10.9 tok/s	17816 ms	114K
Agentic Coding	A	Runs well	10.9 tok/s	25914 ms	114K
Reasoning	A	Runs well	10.9 tok/s	21056 ms	114K
RAG	A	Runs well	10.9 tok/s	32393 ms	114K

Quantization options

How DeepSeek R1 Distill 70B (70B params) fits at each quantization level on Mac Studio M2 Ultra 128GB (92.2 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	27.3 GB	Low	B69
Q3_K_S	3	34.3 GB	Low	A70
NVFP4	4

Get started

Copy-paste commands to run DeepSeek R1 Distill 70B on your machine.

Run

ollama run deepseek-r1:70b

Your hardware

More models your Mac Studio M2 Ultra 128GB can run

Model	Params	Grade	Decode	Capabilities
Devstral 2 123B Instruct	123B	S	6.3 tok/s
Qwen 3.5 122B A10B	122B	S

Frequently asked questions

Can Mac Studio M2 Ultra 128GB run DeepSeek R1 Distill 70B?

Yes, Mac Studio M2 Ultra 128GB can run DeepSeek R1 Distill 70B with a A grade (Runs well). Expected decode speed: 10.9 tok/s.

How much VRAM does DeepSeek R1 Distill 70B need?

DeepSeek R1 Distill 70B (70B parameters) requires approximately 62.3 GB of memory with Q4_K_M quantization.

What is the best quantization for DeepSeek R1 Distill 70B?

The recommended quantization for DeepSeek R1 Distill 70B is Q4_K_M, which balances quality and memory efficiency.

What speed will DeepSeek R1 Distill 70B run at on Mac Studio M2 Ultra 128GB?

On Mac Studio M2 Ultra 128GB, DeepSeek R1 Distill 70B achieves approximately 10.9 tokens per second decode speed with a time-to-first-token of 17816ms using Q4_K_M quantization.

Can Mac Studio M2 Ultra 128GB run DeepSeek R1 Distill 70B for coding?

For coding workloads, DeepSeek R1 Distill 70B on Mac Studio M2 Ultra 128GB receives a A grade with 10.9 tok/s and 114K context.

What context window can DeepSeek R1 Distill 70B use on Mac Studio M2 Ultra 128GB?

On Mac Studio M2 Ultra 128GB, DeepSeek R1 Distill 70B can safely use up to 114K tokens of context. The model's official context limit is 131K, but available memory constrains the safe maximum.

See all results for Mac Studio M2 Ultra 128GB See all hardware for DeepSeek R1 Distill 70B

Embed this result▼

Paste this snippet into any page to show a live fit card.

<iframe src="https://willitrunai.com/embed/deepseek-r1-70b-on-m2-ultra-128gb" width="400" height="180" frameborder="0" style="border:none;border-radius:12px;overflow:hidden;" title="Will It Run AI — fit result"></iframe>

Preview: