What FPS will I get in Path of Exile at 1440p?

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

Does GeForce RTX 4090 VENTUS 3X E OC support DLSS or FSR in Path of Exile?

Path of Exile does not currently support upscalers.

Yes — the GeForce RTX 4090 VENTUS 3X E OC runs Path of Exile at approximately 240 FPS at 1080p Ultra (native, no upscaling).

✓Yes — Excellent

Expected: 240 FPS @ 1080p Ultra (native). This GeForce RTX 4090 VENTUS 3X E OC is currently $3745.00 at Newegg ↗