M3 Pro 18GB vs M4 24GB for local LLMs
1 report on the M3 Pro 18GB and 8 on the M4 24GB
Which is faster for local LLMs?
Nobody has reported the same model at the same quant on both cards yet, so there's no measured head-to-head. Memory bandwidth, which caps how fast a card can write, is 28% higher on the M3 Pro 18GB (154 GB/s on the M3 Pro 18GB, 120 on the M4 24GB). The estimates below compare them on the models people run most.
M3 Pro 18GB
- Memory
- 18GB unified
- Memory bandwidth
- 154 GB/s
- FP16 compute
- 7.4 TFLOPS
- Reports
- 1
M4 24GB
- Memory
- 24GB unified
- Memory bandwidth
- 120 GB/s
- FP16 compute
- 4.3 TFLOPS
- Reports
- 8
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.
| Model | M3 Pro 18GB | M4 24GB |
|---|---|---|
| Qwen3.8 27B | doesn't fit at these settings | 10.8 t/sQ2_K |
| Qwen3.8 125B · 6B active | doesn't fit at these settings | doesn't fit at these settings |
| Qwen3.6 35B · 3B active | doesn't fit at these settings | 35.8 t/sQ2_K |
| DeepSeek V4 Flash 284B · 13B active | doesn't fit at these settings | doesn't fit at these settings |
| Qwen3.6 27B | doesn't fit at these settings | 10.8 t/sQ2_K |
| Gemma 4 26B · 4B active | 35.1 t/sQ2_K | 24.1 t/sQ3_K_S |
Change the context, RAM or model in the calculator: M3 Pro 18GB · M4 24GB
Every report on each card, with its source: M3 Pro 18GB · M4 24GB