Some community-created patches and fixes might help:
Your RTX 4080/7900 XTX is not the problem. GTA IV is a 2008 console port that hates modern hardware. Use DXVK + FusionFix + 60 FPS cap and it will finally run smooth. Gta Iv Lagging On High End Pc
If you follow this article, you should go from "unplayable lag" to "locked 60fps." Here is your final checklist: Some community-created patches and fixes might help: Your
Even on high-end PCs, "Max Settings" can break the game engine. Adjust these specific sliders to avoid unnecessary overhead: Gta Iv Lagging On High End Pc
Ensure you're running the latest graphics drivers for your NVIDIA or AMD graphics card. You can download the latest drivers from: