Will It Run AI

Can DeepSeek R1 671B run on Mac Studio M1 Ultra 128GB?

NO — Won't Fit

F0Won't run
Estimated from fit model

DeepSeek R1 671B needs ~483.6 GB but Mac Studio M1 Ultra 128GB only has 92.2 GB. Try a smaller quantization or lighter model.

Runtime: llama.cppCapacity: No fitBandwidth: HighStack: StandardBottleneck: Memory capacity
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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) — 483.6 GB, exceeds 92.2 GB available
483.6 GB required92.2 GB available
525% VRAM needed

391.4 GB over capacity — needs offload or smaller quantization

Fit status

Too heavy

Decode

2.2 tok/s

TTFT

88851 ms

Safe context

4K

Memory

483.6 GB / 92.2 GB

Offload

80%

Memory breakdown

Weights409.3 GB
KV Cache59.6 GB
Runtime0.9 GB
Headroom13.8 GB

See how fast it feels

With memory offload — actual speed may be lower
See how fast it feelsDeepSeek R1 671B on Mac Studio M1 Ultra 128GB
1st promptCold start — includes initialization
>Solve: If a train travels at 60 mph for 2.5 hours, how far does it go?
Let me work through this step by step. Given information: - Speed = 60 mph (miles per hour) - Time = 2.5 hours Formula: Distance = Speed x Time Calculation: Distance = 60 mph x 2.5 h = 150 miles The train travels 150 miles. Double-check: at 60 mph the train covers 60 miles each hour. In half an hour it covers 30 miles. So in 2.5 hours: 60 + 60 + 30 = 150 miles. Confirmed.
2nd promptWarm — model ready, no init overhead
>What if the train stops for 20 minutes halfway?
The stop doesn't change the total distance covered while moving, but it affects total trip time. Breakdown: - First half: 1.25 hours at 60 mph = 75 miles - Stop: 20 minutes (no distance) - Second half: 1.25 hours at 60 mph = 75 miles Total distance: 150 miles (same) Total time: 2.5 h + 0.33 h = 2.83 hours Average speed: 150 / 2.83 = 53 mph The distance stays the same but average speed drops to 53 mph because of the stop.
Estimated: 2.2 tok/s decode · 88.9s TTFT (warm) · 5 tok/s prefill

What limits this setup

Usable shared or unified memory is the main blocker for this model.

Not enough usable memory

The model needs 483.6 GB, but this setup only exposes 92.2 GB of usable shared or unified memory.

Best improvement path

Move to a larger memory pool

A larger unified-memory SKU or a discrete high-bandwidth GPU is the cleanest way to make this model practical.

Performance by workload

WorkloadGradeFitDecodeTTFTContext
ChatFToo heavy2.2 tok/s48464 ms4K
CodingFToo heavy2.2 tok/s88851 ms4K
Agentic CodingFToo heavy2.2 tok/s129238 ms4K
ReasoningFToo heavy2.2 tok/s105006 ms4K
RAGFToo heavy2.2 tok/s161547 ms4K

Quantization options

How DeepSeek R1 671B (671B params) fits at each quantization level on Mac Studio M1 Ultra 128GB (92.2 GB usable).

QuantBitsVRAMQualityFit
Q2_K
2
261.7 GB
LowF0
Q3_K_S
3
328.8 GB
LowF0
NVFP4
4
375.8 GB
MediumF0
Q4_K_M
4
409.3 GB
MediumF0
Q5_K_M
5
483.1 GB
HighF0
Q6_K
6
550.2 GB
HighF0
Q8_0
8
718.0 GB
Very HighF0
F16
16
1375.6 GB
MaximumF0

Frequently asked questions

Can Mac Studio M1 Ultra 128GB run DeepSeek R1 671B?

No, DeepSeek R1 671B requires more memory than Mac Studio M1 Ultra 128GB provides.

How much VRAM does DeepSeek R1 671B need?

DeepSeek R1 671B (671B parameters) requires approximately 483.6 GB of memory with Q4_K_M quantization.

What is the best quantization for DeepSeek R1 671B?

The recommended quantization for DeepSeek R1 671B is Q4_K_M, which balances quality and memory efficiency.

What speed will DeepSeek R1 671B run at on Mac Studio M1 Ultra 128GB?

On Mac Studio M1 Ultra 128GB, DeepSeek R1 671B achieves approximately 2.2 tokens per second decode speed with a time-to-first-token of 88851ms using Q4_K_M quantization.

Can Mac Studio M1 Ultra 128GB run DeepSeek R1 671B for coding?

For coding workloads, DeepSeek R1 671B on Mac Studio M1 Ultra 128GB receives a F grade with 2.2 tok/s and 4K context.

What context window can DeepSeek R1 671B use on Mac Studio M1 Ultra 128GB?

On Mac Studio M1 Ultra 128GB, DeepSeek R1 671B can safely use up to 4K tokens of context. The model's official context limit is 131K, but available memory constrains the safe maximum.

What should I upgrade first if DeepSeek R1 671B feels slow on Mac Studio M1 Ultra 128GB?

Move to a larger memory pool. A larger unified-memory SKU or a discrete high-bandwidth GPU is the cleanest way to make this model practical.

Is unified memory on Mac Studio M1 Ultra 128GB as fast as VRAM for DeepSeek R1 671B?

Not always. Mac Studio M1 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.

See all results for Mac Studio M1 Ultra 128GBSee all hardware for DeepSeek R1 671B
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