M1 Ultra vs M2 Ultra

Two generations of the highest-RAM Mac chip. M2 Ultra is ~15–20% faster on 8B models, with a higher RAM ceiling.

M1 Ultra and M2 Ultra are both dual-die chips (two Max dies connected via UltraFusion). They sit in Mac Studio and Mac Pro. The practical question for current M1 Ultra owners: does the M2 Ultra offer enough LLM throughput improvement to justify an upgrade?

~15–20% M2 Ultra speed advantage on 8B models

192 GB M2 Ultra max RAM (vs 128 GB for M1 Ultra)

3 models shared benchmark data

2× the cost M2 Ultra is significantly more expensive

Benchmark comparison — 3 shared models

Best published result for each model on each chip. Comparing M1 Ultra 64-core GPU 128 GB vs M2 Ultra 60-core GPU 64 GB — closest matching configs with measured data. Higher tok/s is better.

Model	M1 Ultra (64-core, 128 GB)	M2 Ultra (60-core, 64 GB)	Difference
Llama 3.2 1B Instruct Q4_K - Medium	151.1 tok/s	174.1 tok/s	+15%
Llama 3.1 8B Instruct Q4_K - Medium	54.3 tok/s	59.5 tok/s	+10%
Qwen 2.5 14B Instruct Q4_K - Medium	32.4 tok/s	34.2 tok/s	+6%

M2 Ultra 60-core has slightly fewer GPU cores than M1 Ultra 64-core. The M2 generation bandwidth advantage over M1 is modest — roughly 10–20% depending on the model. Data source: benchmarks.json.

Chip specs compared

Spec	M1 Ultra	M2 Ultra
GPU cores	48 or 64	60 or 76
Memory bandwidth	~800 GB/s	~800 GB/s
Max unified RAM	128 GB	192 GB
Available in	Mac Studio (2022), Mac Pro (2023)	Mac Studio (2023)
70B models at Q4	Yes (fits in 128 GB)	Yes (with more headroom)
105B models at Q4	Tight (needs ~65 GB, fits in 128 GB)	Comfortable (192 GB)

Both generations have similar peak memory bandwidth (~800 GB/s). The M2 generation's efficiency gains come from architectural improvements in how memory is accessed, not a raw bandwidth increase.

Should M1 Ultra owners upgrade to M2 Ultra?

Reasons to stay on M1 Ultra

10–15% throughput gain doesn't change daily workflow
Both chips handle 70B models at Q4 (128 GB both)
M1 Ultra is still a high-performance LLM chip
Cost of upgrade is substantial
M3 Ultra or M4 Ultra will offer larger gains

Reasons to upgrade to M2 Ultra

You need 192 GB RAM for 105B–235B models
The 192 GB ceiling is the primary reason to upgrade
Buying new Mac Studio — M2 Ultra is the right choice now
You're running multiple concurrent model inference tasks

Verdict

M2 Ultra is ~10–15% faster than M1 Ultra — the RAM ceiling (192 GB vs 128 GB) is the real differentiator.

The throughput difference is real but modest — 59.5 vs 54.3 tok/s on 8B models. For most users running 7B–70B models, M1 Ultra remains highly capable. The compelling reason to choose M2 Ultra is the 192 GB option, which enables 235B MoE inference that M1 Ultra can't reach. If you're buying new, M2 Ultra is the better choice. If you own M1 Ultra, wait for M3 or M4 Ultra — those generations deliver more meaningful gains.

Chip pages

M1 Ultra (48-core GPU, 128 GB) M1 Ultra (64-core GPU, 128 GB) M2 Ultra (60-core GPU, 64 GB) M2 Ultra (76-core GPU, 128 GB)

Related comparisons

M2 Ultra vs M3 Ultra M4 Max vs M3 Max All generations compared Best Mac for local LLMs Minimum RAM for 70B models

Data

benchmarks.json — full dataset · chips.json — chip summaries · benchmarks.csv — CSV export

See all chips →