What FPS will I get in Risk of Rain 2 at 1440p?

At 1440p Ultra native, expect around 180 FPS. With DLSS Quality you can push higher.

Does GeForce RTX 5090 ROG Astral LC support DLSS or FSR in Risk of Rain 2?

Yes — Risk of Rain 2 supports dlss2.

Yes — the GeForce RTX 5090 ROG Astral LC runs Risk of Rain 2 at approximately 240 FPS at 1080p Ultra (native, no upscaling).

✓Yes — Excellent

Expected: 240 FPS @ 1080p Ultra (native). This GeForce RTX 5090 ROG Astral LC is currently $4375.62 at Amazon ↗