I'm assuming the GPU scaling makes sure different ratios fit your screen, but I've not tried this one personally. This allows for slightly crisper rendering in games and can be used to improve the image without losing as much performance to anti-aliasing. Since you weren't able to install the drivers while the GTX 1660 was installed, I'm thinking that your system doesn't even detect it when it's disabled (installing a discrete card usually disables the on-board). If you set your monitor in windows to 1920:1080 in 16:9 as is natively supported, then turn on Virtual Super Resolution in the radeon settings, it will allow you to select desktop and game resolutions above what is supported by your monitor (and probably different aspect ratios like 16:10), and then downscale them back to the 1920:1080 of the monitor. Why you may have not seen this previously and been able to select other resolutions that weren't supported by your monitor, is settings under the Radeon settings Display tab labelled Virtual Super Resolution and GPU Scaling. giving it a different aspect ratio may either stretch the picture to fit the screen, or leave the black bars around the picture. Radeon Additional Setting window will open and display the AMD Eyefinity Multi-Display options on the left navigation menu. Click Eyefinity within AMD Radeon Settings. Depending on how individual monitors work. Open AMD Radeon Settings by right-clicking on your desktop and select AMD Radeon Settings. As far as I can tell your monitor is a 16:9 aspect ratio with a maximum of 1920:1080 resolution.
