willitrun·ai

Can Qwen 3 235B A22B run on Mac Studio M2 Ultra 128GB?

YES — With Q2_K

B69Good
Estimated from fit model

Qwen 3 235B A22B needs ~109.2 GB VRAM. Mac Studio M2 Ultra 128GB has 92.2 GB. With Q2_K quantization, expect ~10 tok/s.

Runtime: llama.cppCapacity: OffloadBandwidth: HighStack: StandardBottleneck: Host offload
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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.

Qwen 3 235B A22B at Q4_K_M needs 160.9 GB — too much for Mac Studio M2 Ultra 128GB (92.2 GB). Runs at Q2_K (109.2 GB) with low quality.
Capabilities:

Select quantization to explore

Q4_K_M (Medium quality) 160.9 GB, exceeds 92.2 GB available
160.9 GB required92.2 GB available
175% VRAM needed

68.7 GB over capacity — needs offload or smaller quantization

Fit status

Too heavy

Decode

4.7 tok/s

TTFT

41549 ms

Safe context

4K

Memory

160.9 GB / 92.2 GB

Offload

40%

Memory breakdown

Weights143.4 GB
KV Cache2.9 GB
Runtime0.9 GB
Headroom13.8 GB

See how fast it feels

With memory offload — actual speed may be lower
See how fast it feelsQwen 3 235B A22B on Mac Studio M2 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: 4.7 tok/s decode · 41.5s TTFT (warm) · 12 tok/s prefill

What limits this setup

It fits through host-memory offload, and offload is the main reason performance drops.

CPU or host-memory offload is active

About 20% of the working set spills out of accelerator memory, which usually hurts latency and sustained decode throughput.

Very little memory headroom

You can run the model, but there is not much room left for longer context, bigger batches, extra apps, or future model updates.

Shared-memory contention still exists

The OS, browser, and inference runtime all compete for the same physical memory pool, so real-world headroom is less forgiving than raw capacity suggests.

Best improvement path

Remove offload with more accelerator memory

Prioritize a GPU or unified-memory tier that fits the whole model natively. Removing offload usually helps more than small compute gains.

Buy headroom, not only minimum fit

A slightly larger memory tier gives you safer context growth and makes the recommendation more future-proof.

Increase host RAM if you keep offloading

This setup may need roughly 14.3 GB of extra host RAM just for the offloaded portion, before OS and other tools.

Performance by workload

WorkloadGradeFitDecodeTTFTContext
ChatFToo heavy4.7 tok/s22441 ms4K
CodingFToo heavy4.7 tok/s41549 ms4K
Agentic CodingFToo heavy4.6 tok/s61619 ms4K
ReasoningFToo heavy4.7 tok/s49103 ms4K
RAGFToo heavy4.6 tok/s77024 ms4K

Inference speed

Qwen 3 235B A22B inference speed — tokens per second by GPU & Mac

Estimated decode speed (tokens/sec) for Qwen 3 235B A22B at Q4_K_M across popular GPUs and Apple Silicon, including multi-GPU rigs, using the fastest local runtime per device. Fastest is Mac Studio M3 Ultra 256GB at ~11 tok/s. Speed is memory-bandwidth bound, so cards that fit the whole model in VRAM run far faster than ones that offload to system RAM.

GPU / MacMemoryQuantSpeed (tok/s)Fits?
Mac Studio M3 Ultra 256GB
256 GBQ4_K_M11.3Tight
Mac Studio M2 Ultra 128GB
128 GBQ4_K_M4.7Too big
Mac Studio M1 Ultra 128GB
128 GBQ4_K_M4.4Too big
NVIDIARTX 5090 32GB
32 GBQ4_K_M3.7Too big
2× RX 7900 XTX 24GB
48 GBQ4_K_M3.6Too big
MacBook Pro M4 Max 128GB
128 GBQ4_K_M3.5Too big
MacBook Pro M4 Max 64GB
64 GBQ4_K_M3.2Too big
NVIDIA2× RTX 4090 24GB
48 GBQ4_K_M2.5Too big
NVIDIARTX 4090 24GB
24 GBQ4_K_M2.3Too big
MacBook Pro M3 Max 64GB
64 GBQ4_K_M2.2Too big
RX 7900 XTX 24GB
24 GBQ4_K_M2.1Too big
NVIDIA2× RTX 3090 24GB
48 GBQ4_K_M2.1Too big
NVIDIARTX 4080 Super 16GB
16 GBQ4_K_M2.0Too big
NVIDIARTX 3090 24GB
24 GBQ4_K_M2.0Too big
NVIDIARTX 4070 12GB
12 GBQ4_K_M2.0Too big
NVIDIARTX 3060 12GB
12 GBQ4_K_M2.0Too big
NVIDIARTX 4060 8GB
8 GBQ4_K_M2.0Too big
MacBook Pro M1 Max 64GB
64 GBQ4_K_M2.0Too big
MacBook Pro M4 Pro 48GB
48 GBQ4_K_M2.0Too big
NVIDIA4× RTX 3060 12GB
48 GBQ4_K_M2.0Too big

Estimates for single-stream decoding at Q4_K_M; real tokens/sec varies with prompt length, context, batch size, and runtime build. Prompt processing (prefill) is faster than the decode figures shown here.

Quantization options

How Qwen 3 235B A22B (235B params) fits at each quantization level on Mac Studio M2 Ultra 128GB (92.2 GB usable).

QuantBitsVRAMQualityFit
Q2_K
2
91.7 GB
LowF0
Q3_K_S
3
115.2 GB
LowF0
NVFP4
4
131.6 GB
MediumF0
Q4_K_M
4
143.4 GB
MediumF0
Q5_K_M
5
169.2 GB
HighF0
Q6_K
6
192.7 GB
HighF0
Q8_0
8
251.5 GB
Very HighF0
F16
16
481.7 GB
MaximumF0

Get started

Copy-paste commands to run Qwen 3 235B A22B on your machine.

Run

lms load Qwen3-235B-A22B-Instruct-2507 && lms server start

Opciones de mejora

Hardware que ejecuta bien Qwen 3 235B A22B

Frequently asked questions

Can Mac Studio M2 Ultra 128GB run Qwen 3 235B A22B?

Yes, Mac Studio M2 Ultra 128GB can run Qwen 3 235B A22B at Q2_K quantization (Very compromised (needs ~14.3 GB host RAM)). The recommended Q4_K_M requires 160.9 GB which exceeds available memory, but at Q2_K it needs only 109.2 GB. Expected decode speed: 9.7 tok/s.

How much VRAM does Qwen 3 235B A22B need?

Qwen 3 235B A22B (235B parameters) requires approximately 160.9 GB at Q4_K_M quantization. On Mac Studio M2 Ultra 128GB, it fits at Q2_K using 109.2 GB.

What is the best quantization for Qwen 3 235B A22B?

The recommended quantization is Q4_K_M, but on Mac Studio M2 Ultra 128GB the best fitting quantization is Q2_K, which uses 109.2 GB.

What speed will Qwen 3 235B A22B run at on Mac Studio M2 Ultra 128GB?

On Mac Studio M2 Ultra 128GB, Qwen 3 235B A22B achieves approximately 9.7 tokens per second decode speed with a time-to-first-token of 19939ms using Q2_K quantization.

Can Mac Studio M2 Ultra 128GB run Qwen 3 235B A22B for coding?

For coding workloads, Qwen 3 235B A22B on Mac Studio M2 Ultra 128GB receives a F grade with 4.7 tok/s and 4K context.

What context window can Qwen 3 235B A22B use on Mac Studio M2 Ultra 128GB?

On Mac Studio M2 Ultra 128GB, Qwen 3 235B A22B can safely use up to 4K tokens of context at Q2_K quantization. The model's official context limit is 131K, but available memory constrains the safe maximum.

What should I upgrade first if Qwen 3 235B A22B feels slow on Mac Studio M2 Ultra 128GB?

Remove offload with more accelerator memory. Prioritize a GPU or unified-memory tier that fits the whole model natively. Removing offload usually helps more than small compute gains.

Is unified memory on Mac Studio M2 Ultra 128GB as fast as VRAM for Qwen 3 235B A22B?

Not always. Mac Studio M2 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 M2 Ultra 128GBSee all hardware for Qwen 3 235B A22B
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