M3 Pro 18GB vs AMD RX 6700 XT for local LLMs
1 report on the M3 Pro 18GB and 3 on the AMD RX 6700 XT
Which is faster for local LLMs?
On Qwen3 8B at 4-bit, the M3 Pro 18GB runs at 25.2 tokens per second (one run) and the AMD RX 6700 XT at 61.0 (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 2.5x higher on the AMD RX 6700 XT (154 GB/s on the M3 Pro 18GB, 384 on the AMD RX 6700 XT).
- Memory
- 18GB unified
- Memory bandwidth
- 154 GB/s
- FP16 compute
- 7.4 TFLOPS
- Reports
- 1
- Memory
- 12GB
- Memory bandwidth
- 384 GB/s
- FP16 compute
- 26.4 TFLOPS
- Reports
- 3
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 | M3 Pro 18GB | AMD RX 6700 XT |
|---|---|---|
| Qwen3 8B4-bit | 25.2one run | 61.0one 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 | M3 Pro 18GB | AMD RX 6700 XT |
|---|---|---|
| Qwen3 8B | 33.8 t/sQ3_K_M | 60.3 t/sQ3_K_M |
| Qwen3.8 27B | doesn't fit at these settings | 1.6 t/sQ8_0, layers on CPU |
| Qwen3.8 125B · 6B active | doesn't fit at these settings | doesn't fit at these settings |
| DeepSeek V4 Flash 284B · 13B active | doesn't fit at these settings | doesn't fit at these settings |
| Qwen3.6 35B · 3B active | doesn't fit at these settings | 13.3 t/sQ6_K, experts in RAM |
| Qwen3.6 27B | doesn't fit at these settings | 1.6 t/sQ8_0, layers on CPU |
| Gemma 4 26B · 4B active | 35.1 t/sQ2_K | 62.7 t/sQ2_K |
Change the context, RAM or model in the calculator: M3 Pro 18GB · AMD RX 6700 XT
Every report on each card, with its source: M3 Pro 18GB · AMD RX 6700 XT