Radeon RX 7900 XTX vs RTX 4090: which GPU for local LLMs?
A buy-focused comparison for running LLMs locally. What matters: VRAM first, then generation and price.
At a glance
| Spec | Radeon RX 7900 XTX | RTX 4090 |
|---|---|---|
| VRAM | 24 GB | 24 GB |
| Compatible models (Q4) | 166 | 166 |
| Largest model (Q4) | Salamandra 40B Instruct | Salamandra 40B Instruct |
Which one should you buy?
For larger models (a 70B at Q4, or a comfortable 30B), pick the Radeon RX 7900 XTX and its 24 GB — VRAM is the #1 factor for local LLMs. The RTX 4090 is the pick on a tighter budget or for models up to its 24 GB. Rule of thumb: at equal budget, always take more VRAM.
Where to buy
Radeon RX 7900 XTX
Amazon See Radeon RX 9070 XT 16GB (ASUS Prime OC) →Radeon RX 7900 XTX is no longer sold new at a sane price — current equivalent: Radeon RX 9070 XT 16GB (ASUS Prime OC).
RTX 4090
Amazon See GMKtec EVO-X2 64GB / 1TB (Ryzen AI Max+ 395) →RTX 4090 is no longer sold new at a sane price — current equivalent: GMKtec EVO-X2 64GB / 1TB (Ryzen AI Max+ 395).
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