How much unified memory do I need on a Mac for a 70B model?

Plan for at least 64 GB. A 70B model at Q4 is roughly 40–45 GB of weights, plus 1–4 GB for a 32K context. A 48 GB Mac mini fits it only with heavy quantization and short context; 64 GB is the practical floor, and 96 GB+ gives comfortable headroom.

Is a Mac mini or a Mac Studio better for local LLMs?

The Mac mini is the budget entry and is fine for models up to about 32B. The Mac Studio goes much further on both memory capacity and memory bandwidth, which is what drives generation speed — so for 70B-and-larger models, the Studio is the better machine if you can afford the memory.

Why does memory bandwidth matter more than CPU cores on a Mac?

Local LLM generation is memory-bound: every token requires reading the model weights from memory. The M3 Ultra's ~819 GB/s bandwidth is why it generates faster than a lower-bandwidth chip with the same amount of memory. When comparing Macs for LLMs, read the bandwidth figure before the core count.

Best Mac for Local LLMs 2026: Mac mini vs Mac Studio, Sized by Memory

Quick Answer: The best Mac for local LLMs depends on how big your models are. For models up to ~32B, a Mac mini (M4 Pro) with as much unified memory as you can afford is the value pick. For 70B-and-larger models, step up to a Mac Studio — the M4 Max or, for the most memory bandwidth, the M3 Ultra. The single number that matters most is unified memory (buy at least 64 GB for 70B), and the number that decides speed is memory bandwidth, where the Studio pulls well ahead. Apple keeps changing which memory tiers it offers, so check the current store configs before you buy.

Why Macs are good at this

Apple Silicon uses unified memory: the CPU and GPU share one pool, so a model loaded into RAM is immediately available to the GPU with no separate VRAM copy. That means a Mac with 64 GB can run models that would need multiple discrete GPUs — quietly, and on a fraction of the power.

The two numbers that matter:

Capacity decides what you can run. A 70B model at Q4 is ~40–45 GB, so you want at least 64 GB.
Bandwidth decides how fast. Generation is memory-bound, so the M3 Ultra’s ~819 GB/s is the reason it out-runs chips with the same memory but less bandwidth.

Model	Q4 memory	Comfortable Mac memory
7B–13B	~5–9 GB	16–24 GB
32B	~21 GB	32–48 GB
70B	~42 GB	64 GB (96 GB for headroom)
120B-class	~70 GB	96 GB+

Our top picks at a glance

Mac	Role	Memory bandwidth	Best for
Mac mini (M4 Pro)	Budget entry	Moderate	Up to ~32B models
Mac Studio (M4 Max)	Sweet spot	High	70B at Q4
Mac Studio (M3 Ultra)	Max capacity/speed	~819 GB/s	120B-class, fastest generation

Config warning: Apple has reshuffled its memory tiers through 2026 — some sources report the 64 GB option being removed from the Mac mini M4 Pro, and the top Mac Studio configurations changing. Don’t assume a tier is available; confirm it on Apple’s store (and on Amazon listings) before you commit, and size up rather than down if a tier is borderline for your target model.

1. Mac Studio (M4 Max) — Best Overall for 70B

Apple Mac Studio (M4 Max)

Best overall · upper price class

High memory bandwidth and enough unified memory (configured to 64 GB+) to run 70B models at Q4.
Quiet, compact, and far lower power draw than an equivalent multi-GPU tower.
Configure the memory up — it's the spec that decides which models you can load.

Check Mac Studio M4 Max price on Amazon →

The M4 Max Mac Studio is the Mac we’d point most serious local-LLM users to: enough bandwidth to feel responsive and enough memory to reach 70B. Buying several for a studio or team? A free Amazon Business account adds VAT invoices and quantity pricing. Need to run 120B-class models or want the fastest generation, step up to the M3 Ultra.

2. Mac Studio (M3 Ultra) — Max Capacity and Bandwidth

Apple Mac Studio (M3 Ultra)

Maximum · premium price class

The highest memory bandwidth here (~819 GB/s) — the fastest token generation of any Mac.
Configurable to the most unified memory Apple offers, for 120B-class models.
Overkill (and over-budget) unless you genuinely run the biggest models.

Check Mac Studio M3 Ultra price on Amazon →

3. Mac mini (M4 Pro) — Best Budget Entry

Apple Mac mini (M4 Pro)

Best value · entry price class

The cheapest way into Apple Silicon for local AI — great for models up to ~32B.
Configure as much unified memory as the budget allows; 48 GB is tight for 70B.
Tiny, silent, and low-power — a tidy always-on LLM box.

Check Mac mini M4 Pro price on Amazon →

How to choose

Buy memory, and buy it up front. Unified memory isn’t user-upgradeable, so the config you buy is the config you keep. Size it to the biggest model you realistically want to run.
Read bandwidth, not just cores. For generation speed, the memory-bandwidth figure (highest on the M3 Ultra) matters more than core counts.
Match the machine to the model. Up to 32B, a Mac mini is plenty. For 70B, you want a Mac Studio with 64 GB+. For 120B-class, only the top Studio configs apply.
Verify the tier is still sold. Apple’s memory options have shifted in 2026 — confirm availability before planning around a specific capacity.

Mac vs. the alternatives

A Mac Studio competes directly with a Strix Halo mini PC and NVIDIA’s DGX Spark. The Mac typically wins on memory bandwidth (and therefore speed), while the Strix Halo box is cheaper and the DGX Spark offers native CUDA. If your models fit in 24–32 GB and you want maximum speed per dollar, a discrete GPU still beats all of them.

The bottom line

For most people, a Mac Studio (M4 Max) configured with 64 GB+ is the best Mac for local LLMs — enough memory and bandwidth for 70B models in a quiet, efficient box. Drop to a Mac mini (M4 Pro) if your models stay under ~32B, or climb to the M3 Ultra only if you run 120B-class models and want the fastest generation. Whatever you pick, buy the memory first and confirm the config is still on sale.