How Baldur's Gate 3 runs on the GeForce RTX 4090
Our estimate puts the GeForce RTX 4090 at about 255 fps on High at 1080p in Baldur's Gate 3, which means it runs comfortably. On Low the same card manages about 300+ fps, and on Ultra about 184.
The graphics card is the limit here, so lowering the resolution or the quality preset is what raises your frame rate.
For a steady 60 fps, our estimate says: 1080p: Ultra (about 184 fps); 1440p: Ultra (about 132 fps); 4K: Ultra (about 74 fps).