AMD RX 6900 XT 16GB vs AMD RX 9070 for local LLMs
2 reports on the AMD RX 6900 XT 16GB and 6 on the AMD RX 9070
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 25% higher on the AMD RX 9070 (512 GB/s on the AMD RX 6900 XT 16GB, 640 on the AMD RX 9070). The estimates below compare them on the models people run most.
AMD RX 6900 XT 16GB
- Memory
- 16GB
- Memory bandwidth
- 512 GB/s
- FP16 compute
- 46.1 TFLOPS
- Reports
- 2
AMD RX 9070
- Memory
- 16GB
- Memory bandwidth
- 640 GB/s
- FP16 compute
- 145 TFLOPS
- Reports
- 6
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 | AMD RX 6900 XT 16GB | AMD RX 9070 |
|---|---|---|
| Qwen3.8 27B | 33.4 t/sQ2_K | 41.7 t/sQ2_K |
| 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 | 110.4 t/sQ2_K | 138.0 t/sQ2_K |
| Qwen3.6 27B | 33.4 t/sQ2_K | 41.7 t/sQ2_K |
| Gemma 4 26B · 4B active | 74.4 t/sQ3_K_S | 93.0 t/sQ3_K_S |
Change the context, RAM or model in the calculator: AMD RX 6900 XT 16GB · AMD RX 9070
Every report on each card, with its source: AMD RX 6900 XT 16GB · AMD RX 9070