M4 Max 128GB vs AMD RX 6700 XT for local LLMs
52 reports on the M4 Max 128GB and 4 on the AMD RX 6700 XT
Which is faster for local LLMs?
On Gemma 4 12B at 4-bit, the M4 Max 128GB has 54.5 generation tokens/s (one run); prompt processing 589.0 tokens/s (one run); the AMD RX 6700 XT has 34.6 generation tokens/s (one run); prompt processing 653.9 tokens/s (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 42% higher on the M4 Max 128GB (546 GB/s on the M4 Max 128GB, 384 on the AMD RX 6700 XT).
- Memory
- 128GB unified
- Memory bandwidth
- 546 GB/s
- FP16 compute
- 18.4 TFLOPS
- Reports
- 52
- Memory
- 12GB
- Memory bandwidth
- 384 GB/s
- FP16 compute
- 26.4 TFLOPS
- Reports
- 4
Measured on both
Generation and prompt processing speeds 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 bit class. Each side shows the engines and reported context behind its median. Context can mean a configured window or prompt depth, so these are community comparisons with differing settings. How to read these
| Model | M4 Max 128GB | AMD RX 6700 XT |
|---|---|---|
| Gemma 4 12B4-bit | 54.5one runPP 589.0 (one run)llama.cppcontext not stated | 34.6one runPP 653.9 (one run)llama.cpp8K context |
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 | AMD RX 6700 XT |
|---|---|---|
| Gemma 4 12B | 15.2 t/sFP16 | 31.3 t/sQ4_K_M |
| Qwen3.8 27B | 6.7 t/sFP16 | 1.6 t/sQ8_0, layers on CPU |
| Qwen3.8 125B · 6B active | 30.7 t/sQ5_K_S | doesn't fit at these settings |
| Qwen3.6 35B · 3B active | 21.2 t/sFP16 | 13.3 t/sQ6_K, experts in RAM |
| DeepSeek V4 Flash 284B · 13B active | 48.3 t/sQ2_K | doesn't fit at these settings |
| Qwen3.6 27B | 6.7 t/sFP16 | 1.6 t/sQ8_0, layers on CPU |
| Gemma 4 26B · 4B active | 18.2 t/sFP16 | 62.7 t/sQ2_K |
Change the context, RAM or model in the calculator: M4 Max 128GB · AMD RX 6700 XT
Every report on each card, with its source: M4 Max 128GB · AMD RX 6700 XT