By scaling back to 90 percent, you'll only be pushing 1,866,240 pixels. If you're gaming at 1920x1080, you're trying to push 2,073,600 pixels through the GPU. If you decrease the resolution scale to 90 percent, the game will tell the GPU that it only needs an image that's 90 percent of the actual output image. By default, it's set at 100 percent, meaning that your GPU will render the image exactly at the resolution you've set (like, say, 1920x1080). The resolution scale is an interesting setting, and controls supersampling/upscaling. The amount of motion blur defaults to 50 percent, and we think it's just fine there. Motion blur causes moving objects to blur, giving them a better sense of motion or speed. Using a wider field of view will make the player models for the hands and weapons appear skinnier, however. However, some players prefer wider fields of view, allowing them to see more of the battlefield. Unless you're using an ultrawide monitor, we generally recommend leaving this alone.
This option has a range of 44 to 109 degrees and defaults to 55. The field of view affects the, well, field of view of the screen. If you're playing for fun, however, we recommend turning it on to keep tearing in check. Since we look for raw frame rates during testing, we usually keep vertical sync turned off. G-Sync and FreeSync options are controlled by using the appropriate control panel application on the desktop. If you have a video card and monitor combination that can use FreeSync or G-Sync, those features will drop your monitor's refresh rate to match your frame rate on the fly if the frame rate falls below the maximum monitor refresh rate. This is not the same thing as G-Sync (Nvidia) or FreeSync (AMD). This can help prevent tearing, which can look nasty and is really noticeable in first-person shooters like Battlefront. Vertical sync (vsync) will attempt to lock your frame rate to the refresh rate of your monitor, so long as you're achieving frame rates higher than your monitor refresh rate. The options available will change based on the monitor you use. This setting allows you to set the refresh rate for your monitor.
Most people will want to play in fullscreen mode. This pretty much sets whether you play in fullscreen mode, windowed mode, or in a borderless window.