RTX 3080 Ti vs RX 7900 XT for local AI
The RX 7900 XT fits more: up to Gemma 3 27B, against Qwen3 14B on the RTX 3080 Ti. The RTX 3080 Ti generates about 14% faster on any model both can run, because it has 912 GB/s of memory bandwidth to the RX 7900 XT's 800 GB/s.
Memory and bandwidth
Memory decides which models fit. Bandwidth decides how fast they generate, because every token reads the model's active weights once.
| RTX 3080 Ti | RX 7900 XT | |
|---|---|---|
| Memory | 12 GB VRAM | 20 GB VRAM |
| Bandwidth | 912 GB/s | 800 GB/s |
| Biggest model that fits | Qwen3 14B | Gemma 3 27B |
| Best everyday pick | Qwen3 14B, ~54 tok/s | Gemma 3 27B, ~26 tok/s |
Every model, side by side
Estimated generation speed at the largest memory size each was sold in (12 GB and 20 GB).
| Model | RTX 3080 Ti | RX 7900 XT |
|---|---|---|
| Qwen3 4B About 4 GB | ~200 tok/s Runs great | ~180 tok/s Runs great |
| Qwen3 8B About 7 GB | ~96 tok/s Runs great | ~85 tok/s Runs great |
| Gemma 3 12B About 10 GB | ~62 tok/s Runs great | ~54 tok/s Runs great |
| Qwen3 14B About 11 GB | ~54 tok/s Runs great | ~47 tok/s Runs great |
| gpt-oss 20B About 16 GB | Needs 16 GB | ~140 tok/s Runs great |
| Gemma 3 27B About 19 GB | Needs 19 GB | ~26 tok/s Usable |
| Qwen3 30B-A3B About 21 GB | Needs 21 GB | Needs 21 GB |
| Qwen3 32B About 22 GB | Needs 22 GB | Needs 22 GB |
| Llama 3.3 70B About 45 GB | Needs 45 GB | Needs 45 GB |
| gpt-oss 120B About 67 GB | Needs 67 GB | Needs 67 GB |
| Qwen3 235B-A22B About 144 GB | Needs 144 GB | Needs 144 GB |
| DeepSeek R1 671B About 406 GB | Needs 406 GB | Needs 406 GB |
It depends. The RX 7900 XT fits bigger models; the RTX 3080 Ti runs the models both fit faster. Price matters as much as either number: check used prices on the builds page, where every parts list has a measured or estimated speed.
Both columns use the same formula: memory bandwidth divided by the weights read per token, calibrated on our own rack, with Ollama's default 4-bit sizes. Real results are usually within about a third. Measured either one? Send us the number.