As we reported earlier this summer, Bethesda has a collaboration with AMD for Starfield, and thanks to this, FSR 2.0 (Fidelity FX Super Resolution 2.0) is supported day one. Unfortunately, deals like these usually means the competition's alternative isn't supported, which means no DLSS for Nvidia users.
At least that was true until a few hours after the game was released today (for people who have bought the deluxe editions), because there are always crafty modders. As noted by Idle Sloth, Nexusmods.com already has a solution which replaces FSR2 with DLSS or XeSS, and it's free of charge.
We haven't tried it ourselves yet, but judging by the comments, it is actually working. Have you started your Starfield space adventure yet? Remember to check out our review where we tell you everything you need to know.