08-09-2018, 06:58 AM
The older driver (which is default if you are on an older image) actually copies the HDMI framebuffer and sends it to the display and also has more issues with scaling up/down resolutions. Using a 16:9 resolution would also squish the image on the display. If you are on a newer image, you should be able to go to the RetroPie menu and the new display driver, which could potentially solve your issue, but would probably still squish the image if you used the 16:9 resolution, so I'd recommend using one of the modes that is higher resolution but is 4:3 or trying the 1024x768 HDMI mode if that was not the default.