The M1 for local AI.

The M1 has up to 16 GB of unified memory, read at up to 68 GB/s. Here's what that means for running language models on a Mac with it, worked out from Apple's own figures.

1The specs that matter for AI

Unified memory16 GB
Memory bandwidth68 GB/s
Found inMacBook Air (2020), 13-inch MacBook Pro (2020), Mac mini (2020), iMac (2021)
Dedicated seat for itCore seat: mines up to 20 MLX a day

2Which models fit

At 4 bits per weight a model needs a little over half a gigabyte per billion parameters, plus room for its context and macOS. With 16 GB, the M1 comfortably holds models up to about 21 billion parameters.

Model at 4-bitMemory it needsFits on the M1
8B model4.5 GBYes
14B model7.9 GBYes
32B model18 GBNo
70B model39.4 GBNo
gpt-oss-120b, mixture-of-experts65 GBNo
Qwen3.5-397B-A17B, mixture-of-experts223.3 GBNo
DeepSeek-V4.1-Flash, mixture-of-experts316 GBNo

3How fast it runs

Writing text is limited by memory bandwidth: every new token reads the model's active weights once. Dividing the M1's 68 GB/s by the bytes read per token gives the ceiling below. Real runs usually reach about 45% to 80% of it (llama.cpp benchmarks).

Model at 4-bitRead per tokenCeiling for one chat
8B model4.5 GB15 tokens/s
14B model7.9 GB9 tokens/s

5Compare with other chips

6Questions

Can the M1 run a 70B model?
Not comfortably. A 70B model at 4-bit needs about 40 GB, and the M1 has at most 16 GB. Models up to about 21B parameters fit well.
How many tokens per second does the M1 get?
For an 8B model at 4-bit, the ceiling is about 15 tokens a second, and real runs reach roughly half to four fifths of it. Bigger models are proportionally slower.
Is the M1 good for AI?
For running models locally, memory and bandwidth matter most. The M1 has up to 16 GB at 68 GB/s, enough for models up to about 21 billion parameters. It can also earn by running AI work for MLX Network with MLX Node.

Sources

  1. Apple: M1apple.com
  2. llama.cpp: Apple Silicon benchmarksgithub.com
M1 for local LLMs: memory, speed and what fits | MLX