With PowerXpresss, the ASUS S200E series can configure the notebook so that it automatically uses the integrated GPU when powered by battery, and uses the standalone GPU when connected to AC power. From the Graphics Settings tree, click PowerXpress.
Select to automatically select the power-saving GPU when using battery, click [OK]. If prompted, make sure to close any open applications and click OK in the message dialog box that appears to proceed with the GPU switch.
Note: If automatic switching is enabled, it is strongly recommended to close all applications before changing the power of the notebook to prevent unexpected application behavior. By default, a message dialog box appears every time you switch GPUs. To disable this dialog box for subsequent switches, select Don't show this warning again, switch automatically.
Note: During the switching process, the monitor will normally be black for a period of time. Graphics processing responsibility will automatically switch to the appropriate GPU, and the PowerXpress Status box will update to reflect the GPU in use.