It's running slow on your RX590.
It's running slow on your RX590.
It seems the game is efficiently utilizing only half of your GPU while minimizing MSAA, leaving more work to the CPU. The CPU threads are fully engaged. The issue might be with the game's code or settings, possibly requiring further research. Search terms like "GTA 5 GPU usage" or "CPU bottleneck GTA 5" could help.
I've noticed GTA V doesn't perform well on most AMD CPUs and GPUs. I'm still unsure about it. Regarding bottlenecks, I spent about six months looking for the right components before finding a good site that helped me optimize my setup. My recommended page is https://pc-builds.com/calculator/Ryzen_5...Pl12V28/16. It seems some YouTube users who ran the game with this GPU managed to achieve around 100 FPS even at maximum settings.
Reduce Ultra's brightness to medium to high. Consider removing tessellation slightly and disable Vsync for smoother performance above 60fps.
8x SSAA refers to operating at double the standard resolution, which translates to roughly twice the demands compared to 4K. Newer graphics cards may encounter problems when handling 4K, so increasing the load further can become quite challenging, even for older titles.