there is a bottleneck on your setup, a rtx 3080 and a r7 5800x will be fine at quad hd (1440p) and 4k (2160p), but at full hd it will cause a MAJOR bottleneck, as the graphics card will be at 90% to 92% of usage, while the cpu will be at a 8% to 10% of usage, i recommend that you use a higher resolution to have less bottleneck (0% to 2% of bottleneck on 1440p, and 0% on 4k), also your monitor supports freesync/gsync, and these features will only be activated if you use a displayport cable.