NVIDIA RTX 3080 20GB vs NVIDIA RTX 5080 for local LLMs
14 reports on the NVIDIA RTX 3080 20GB and 26 on the NVIDIA RTX 5080
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 26% higher on the NVIDIA RTX 5080 (760 GB/s on the NVIDIA RTX 3080 20GB, 960 on the NVIDIA RTX 5080). The estimates below compare them on the models people run most.
NVIDIA RTX 3080 20GB
- Memory
- 20GB
- Memory bandwidth
- 760 GB/s
- FP16 compute
- 119 TFLOPS
- Reports
- 14
NVIDIA RTX 5080
- Memory
- 16GB
- Memory bandwidth
- 960 GB/s
- FP16 compute
- 225 TFLOPS
- Reports
- 26
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 | NVIDIA RTX 3080 20GB | NVIDIA RTX 5080 |
|---|---|---|
| Qwen3.8 27B | 35.4 t/sQ3_K_M | 62.6 t/sQ2_K |
| Qwen3.8 125B · 6B active | 19.1 t/sQ2_K, experts in RAM | doesn't fit at these settings |
| Qwen3.6 35B · 3B active | 140.5 t/sQ3_K_S | 207.0 t/sQ2_K |
| DeepSeek V4 Flash 284B · 13B active | doesn't fit at these settings | doesn't fit at these settings |
| Qwen3.6 27B | 35.4 t/sQ3_K_M | 62.6 t/sQ2_K |
| Gemma 4 26B · 4B active | 79.7 t/sQ4_K_S | 139.6 t/sQ3_K_S |
Change the context, RAM or model in the calculator: NVIDIA RTX 3080 20GB · NVIDIA RTX 5080
Every report on each card, with its source: NVIDIA RTX 3080 20GB · NVIDIA RTX 5080