De acordo com o review do Adrenaline.
Os números são esses:
RTX 2080 x GTX 1080
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Assassin's Creed Origins - 1920x1080, DX11, Altíssima
30%+
Battlefield 1 - 1920x1080, DX11, Ultra
+34%
Grand Theft Auto V - 1920x1080, DX11, Pass 4, Ultra
+10%
Middle-Earth Shadow of War - 1920x1080, DX11, Ultra
+30%
Project Cars 2 - 1920x1080, DX11, Ultra
+37%
Shadow of Tomb Raider - 1920x1080, DX12, Ultra
+32%
Tom Clancy's The Division - 1920x1080, DX11, Ultra
+25%
The Witcher 3 Wild Hunt - 1920x1080, DX11, Ultra
+42%
Em média: A RTX 2080 é 30% superior a GTX 1080