NVIDIA RTX 3090 vs NVIDIA RTX 5080 for local LLMs
219 reports on the NVIDIA RTX 3090 and 29 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 about the same on both (936 GB/s on the NVIDIA RTX 3090, 960 on the NVIDIA RTX 5080). The estimates below compare them on the models people run most.
NVIDIA RTX 3090
- Memory
- 24GB
- Memory bandwidth
- 936 GB/s
- FP16 compute
- 142 TFLOPS
- Reports
- 219
NVIDIA RTX 5080
- Memory
- 16GB
- Memory bandwidth
- 960 GB/s
- FP16 compute
- 225 TFLOPS
- Reports
- 29
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 3090 | NVIDIA RTX 5080 |
|---|---|---|
| Qwen3.8 27B | 33.9 t/sQ4_K_M | 62.6 t/sQ2_K |
| Qwen3.8 125B · 6B active | 19.4 t/sQ2_K, experts in RAM | doesn't fit at these settings |
| Qwen3.6 35B · 3B active | 120.1 t/sQ4_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 | 33.9 t/sQ4_K_M | 62.6 t/sQ2_K |
| Gemma 4 26B · 4B active | 76.4 t/sQ5_K_S | 139.6 t/sQ3_K_S |
Change the context, RAM or model in the calculator: NVIDIA RTX 3090 · NVIDIA RTX 5080
Every report on each card, with its source: NVIDIA RTX 3090 · NVIDIA RTX 5080