Can It Run?
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Can an M3 Max 128GB Mac run DeepSeek R1?

M3 Max · 128 GB unified memory · 400 GB/s · MacBook Pro 16" (M3 Max)

No — not at Q4_K_M.

DeepSeek R1 needs about 411.3 GiB but an M3 Max 128GB Mac has only ~112.0 GiB available for a model — you are 299.3 GiB short. macOS will swap to SSD and generation will crawl.

Weights
390.5 GiB
684.49B params @ Q4_K_M
KV cache
0.5 GiB
8K context, FP16
Overhead
20.3 GiB
runtime + activations
Total needed
411.3 GiB
of ~112.0 GiB usable
Est. speed
9 tok/s
400 GB/s bandwidth
Max context
n/a
at Q4_K_M

Where the memory goes

Three things occupy memory when a model is loaded: the weights themselves, the KV cache that holds the conversation, and the runtime's own working buffers. Only the first is fixed — the KV cache grows with every token in your context.

QuantisationWeightsTotalTok/sFits?
FP161275.0 GiB1340.0 GiB3No
Q8_0677.3 GiB712.5 GiB5No
Q6_K525.9 GiB553.6 GiB6No
Q5_K_M454.2 GiB478.3 GiB7No
Q4_K_M390.5 GiB411.3 GiB9No
Q3_K_M310.8 GiB327.6 GiB11No
Q2_K239.1 GiB252.3 GiB14No

The default. Best quality-per-gigabyte for most people.

How long a context fits

The KV cache is often what breaks a setup that looked fine at load time. Quantising it to 8-bit roughly halves its footprint with little measurable quality cost.

ContextKV cacheTotalFP16 KVQ8 KV
2K0.1 GiB410.7 GiBNoNo
4K0.3 GiB410.9 GiBNoNo
8K0.5 GiB411.3 GiBNoNo
16K1.1 GiB412.2 GiBNoNo
32K2.2 GiB413.8 GiBNoNo
128K8.6 GiB423.9 GiBNoNo

What to run instead on an M3 Max 128GB Mac

These are the largest models that fit comfortably on this machine at Q4_K_M with an 8K context.

ModelSizeTotalTok/s
gpt-oss-120b116.8B71.3 GiB64Yes, comfortably
Qwen2.5 72B72.7B46.8 GiB7Yes, comfortably
DeepSeek-R1-Distill-Llama-70B70.6B45.6 GiB7Yes, comfortably
Llama 3.3 70B70.6B45.6 GiB7Yes, comfortably
Mixtral 8x7B46.7B29.8 GiB25Yes, comfortably
DeepSeek-R1-Distill-Qwen-32B32.8B22.4 GiB16Yes, comfortably

Macs that run DeepSeek R1 comfortably

The smallest configuration that handles it is the M3 Ultra 512GB (Mac Studio (M3 Ultra)).

MacMemoryBandwidthTok/s
M3 Ultra 512GB512 GB819 GB/s18

Common questions

Can an M3 Max 128GB Mac run DeepSeek R1?
No. At Q4_K_M it needs about 411.3 GiB, and an M3 Max 128GB Mac has roughly 112.0 GiB available for a model after macOS takes its share.
How fast is DeepSeek R1 on an Mac?
Around 9 tokens per second. Token generation on Apple Silicon is limited by memory bandwidth, and this machine has 400 GB/s. Because this is a mixture-of-experts model only 37.44B of its 684.49B parameters are read per token, which is why it is faster than its size suggests.
How much memory does DeepSeek R1 need?
390.5 GiB for the weights at Q4_K_M, plus 0.5 GiB for an 8K-token KV cache and about 20.3 GiB of runtime overhead — 411.3 GiB in total.