M4 Max 128GB vs M4 Max 64GB for local LLMs
15 reports on the M4 Max 128GB and 5 on the M4 Max 64GB
Which is faster for local LLMs?
On Qwen3.8 125B · 6B active at 3-bit, the M4 Max 128GB runs at 27.3 tokens per second (one run) and the M4 Max 64GB at 52.6 (one run). Those are community reports whose engines and settings differ, so the gap is a rough sign, not a controlled measure of the two cards. Memory bandwidth, which caps how fast a card can write, is about the same on both (546 GB/s on the M4 Max 128GB, 546 on the M4 Max 64GB).
- Memory
- 128GB unified
- Memory bandwidth
- 546 GB/s
- FP16 compute
- 18.4 TFLOPS
- Reports
- 15
- Memory
- 64GB unified
- Memory bandwidth
- 546 GB/s
- FP16 compute
- 18.4 TFLOPS
- Reports
- 5
Measured on both
Median tokens per second from plain runs (one device, one request, no speculative decoding, the whole model in the device's memory) of the same model size at the same quant level. Engines and context lengths can still differ between the runs. How to read these
| Model | M4 Max 128GB | M4 Max 64GB |
|---|---|---|
| Qwen3.8 125B · 6B active3-bit | 27.3one run | 52.6one run |
Estimated by the calculator
The quant the calculator recommends for each card and its estimated speed at a 32,768-token context with 32 GB of system RAM, from memory bandwidth and the model's shape. Where a model was also measured above, the measurement wins.
| Model | M4 Max 128GB | M4 Max 64GB |
|---|---|---|
| Qwen3.8 125B · 6B active | 30.7 t/sQ5_K_S | 61.4 t/sQ2_K |
| Qwen3.8 27B | 6.7 t/sFP16 | 13.5 t/sQ8_0 |
| DeepSeek V4 Flash 284B · 13B active | 48.3 t/sQ2_K | doesn't fit at these settings |
| Qwen3.6 35B · 3B active | 21.2 t/sFP16 | 42.5 t/sQ8_0 |
| Qwen3.6 27B | 6.7 t/sFP16 | 13.5 t/sQ8_0 |
| Gemma 4 26B · 4B active | 18.2 t/sFP16 | 36.4 t/sQ8_0 |
| DeepSeek V4.1 Flash 552B · 16B active | doesn't fit at these settings | doesn't fit at these settings |
Change the context, RAM or model in the calculator: M4 Max 128GB · M4 Max 64GB
Every report on each card, with its source: M4 Max 128GB · M4 Max 64GB