Can an Apple M4 Pro 48GB run Qwen3 32B?
Yes
At IQ4_XS it needs 18.62 GB of the 36 GB available and generates around 10.4 tokens per second at an 8k context window.
In practice
Qwen3 32B sits comfortably on Apple M4 Pro 48GB. At IQ4_XS it takes 18.62 GB of the 36 GB available, which leaves 17.38 GB spare, enough for the 8k window we assumed and for a window of up to about 32k tokens before memory runs out. Generation runs at about 10.4 tokens per second, faster than most people read, so a 500-token answer takes about 50 seconds.
Of the memory in use, 87% is the weights and 11% is the attention cache. With this much room the question is quality, not fit. The next step up, Q4_K_M, also fits at 20.83 GB, but runs at 9.3 tokens per second, so IQ4_XS is where we would stay.
Reading a 4,000-token prompt, roughly a long email or a few pages of text, takes about 2 minutes before the first word appears. That part is limited by compute and not by bandwidth, so it follows a different spec from the writing speed.
The numbers
Qwen3 32B has 32.76 billion parameters across 64 layers. The Apple M4 Pro 48GB has 48 GB of unified memory at 273 GB/s, of which about 36 GB is left for a model once the operating system has taken its share.
| Quantization | Total needed | Fits | Speed |
|---|---|---|---|
| Q8_0 | 34.83 GB | yes | 5.5 t/s |
| Q6_K | 27.43 GB | yes | 7.0 t/s |
| Q5_K_M | 24.11 GB | yes | 8.0 t/s |
| Q4_K_M | 20.83 GB | yes | 9.3 t/s |
| IQ4_XS | 18.62 GB | yes | 10.4 t/s |
| Q3_K_M | 17.32 GB | yes | 11.2 t/s |
| IQ3_XXS degraded | 14.08 GB | yes | 13.9 t/s |
| Q2_K degraded | 15.19 GB | yes | 12.8 t/s |
| IQ2_XXS degraded | 10.27 GB | yes | 19.2 t/s |
9 of the 9 levels fit entirely. Levels marked degraded are listed for completeness, not as advice.
How long a conversation it holds
Memory rises with the length of the conversation because the attention cache keeps a key and a value for every token. At IQ4_XS, the longest window that still fits on this device is 32k tokens. Setting the window to what you need and no more is the cheapest way to buy back memory.
| Context | Cache | Total | Fits |
|---|---|---|---|
| 4k | 1 GB | 17.62 GB | yes |
| 8k | 2 GB | 18.62 GB | yes |
| 16k | 4 GB | 20.62 GB | yes |
| 32k | 8 GB | 24.62 GB | yes |
The settings we would use
llama-server -m <model>.gguf -ngl all -c 8192 -fa on
In Ollama, set OLLAMA_CONTEXT_LENGTH to the window you want, run ollama ps while the model is loaded and check that
the processor column reads 100% GPU. If it shows a split on a model that fits, the Ollama guide shows how to fix it.
The llama.cpp flags guide explains each option above.
What else an Apple M4 Pro 48GB runs well
For comparison, these are the other popular models that fit this device at a sound quantization, best pairings first.
| Model | Quantization | Memory | Speed |
|---|---|---|---|
| Qwen3 30B A3B | Q8_0 | 31.27 GB | 26.8 t/s |
| GPT OSS 20B | MXFP4 | 11.81 GB | 45.1 t/s |
| Qwen3.5 9B | Q8_0 | 10.22 GB | 21.0 t/s |
| Qwen3.5 27B | Q5_K_M | 19.46 GB | 10.2 t/s |
The same model on nearby hardware
Memory decides whether Qwen3 32B loads and bandwidth decides how quickly it answers. Here is what a step down, a card with the same memory and a step up do with it.
| Device | Memory | Bandwidth | Result |
|---|---|---|---|
| Apple M3 Max 36GB | 36 GB | 400 GB/s | does not fit |
| Apple M4 Max 64GB | 64 GB | 546 GB/s | Q8_0, 11.0 t/s |
See how fast it feels
Apple M4 Pro 48GB running Qwen3 32B at IQ4_XS
YouWhy does my model use more memory when the conversation gets longer?
Reading your question
Simulated from our estimate at a 512-token question, not a recording. Assumes nothing else is competing for the GPU.
Questions people ask
How much VRAM does Qwen3 32B need on Apple M4 Pro 48GB?
At Q4_K_M with an 8k context window it needs 20.83 GB in total: 18.42 GB of weights, 2 GB of KV cache and 0.41 GB of runtime overhead. The Apple M4 Pro 48GB makes about 36 GB available once the operating system has taken its share.
What context length can Apple M4 Pro 48GB handle with Qwen3 32B?
At IQ4_XS the longest window that still fits is about 32k tokens. Memory grows with the window, so a shorter one leaves room for a higher quantization.
How fast is Qwen3 32B on Apple M4 Pro 48GB?
We estimate about 10.4 tokens per second at IQ4_XS, which is faster than most people read. A 500-token answer takes about 50 seconds. Memory bandwidth of 273 GB/s sets that ceiling, and the estimate is good to about 10 to 30 percent.
Keep going
Everything the Apple M4 Pro 48GB runs, the full breakdown for Qwen3 32B, how the numbers are made in the methodology, or a different pairing in the calculator.