AMD RX 6700 XT vs AMD RX 7800 XT 16GB for local LLMs
3 reports on the AMD RX 6700 XT and 3 on the AMD RX 7800 XT 16GB
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 1.6x higher on the AMD RX 7800 XT 16GB (384 GB/s on the AMD RX 6700 XT, 624 on the AMD RX 7800 XT 16GB). The estimates below compare them on the models people run most.
AMD RX 6700 XT
- Memory
- 12GB
- Memory bandwidth
- 384 GB/s
- FP16 compute
- 26.4 TFLOPS
- Reports
- 3
AMD RX 7800 XT 16GB
- Memory
- 16GB
- Memory bandwidth
- 624 GB/s
- FP16 compute
- 75 TFLOPS
- Reports
- 3
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 6700 XT | AMD RX 7800 XT 16GB |
|---|---|---|
| Qwen3.8 27B | 1.6 t/sQ8_0, layers on CPU | 40.7 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 | 13.3 t/sQ6_K, experts in RAM | 134.6 t/sQ2_K |
| Qwen3.6 27B | 1.6 t/sQ8_0, layers on CPU | 40.7 t/sQ2_K |
| Gemma 4 26B · 4B active | 62.7 t/sQ2_K | 90.7 t/sQ3_K_S |
Change the context, RAM or model in the calculator: AMD RX 6700 XT · AMD RX 7800 XT 16GB
Every report on each card, with its source: AMD RX 6700 XT · AMD RX 7800 XT 16GB