If you’re using Windows 8.1 on a device with a high resolution screen, you can bump up the Start screen tile density and display more tile rows on the screen. This interface, which also exists in the initial versions of Windows 8/RT, takes on additional interest with Windows 8.1 because of the coming proliferation of devices with high DPI screens.
The Show More Tiles setting is also useful on small devices, like the Acer Iconia W3, which features an 8.1-inch screen with a resolution of 1280 x 800. That may not seem like a particularly high resolution, but the setting only appears on devices that have certain combinations of physical screen size and screen resolution. So Show More Tiles appears on the W3, but it doesn’t appear on my Samsung Series 9 laptop, which has a large physical screen (15 inches) but a relatively low resolution of 1600 x 900 (for that screen).
On that W3, as on many Windows 8/RT devices, the default view is three rows of tiles.
To see whether Show More Tiles is available, navigate to the Start screen and access the Settings charm (WINKEY + I from the keyboard). Then, choose Tiles from the Settings pane that appears. If you see a Show More Tiles option at the top of the pane, you can enable this settings to change the number of tile rows that appear.
When enabled, the W3 now shows four rows of tiles in the standard landscape view.
This change also affects portrait view, of course. On the W3, the number of tile rows jumps from 6 to 8, for example.