The switch between Energy Saving and High Performance graphics modes may be blocked. When this happens, an exclamation mark is shown over the nVidia Graphics Mode icon in the system notification area. After left-clicking on the Graphics Mode icon, a small dialog window will open and the top-most link will say Save energy now or Increased performance now. An example of this is shown in the image below.
After clicking on this top-most link, if there is an application which is blocking the switch, a window is shown listing which application(s) are blocking the switch. Once these applications are closed, clicking on the top-most link again will perform the graphics mode switch. An example of the dialog is shown in the image below.
The switch between graphics modes is blocked when an application makes use of certain DirectX or OpenGL functions, because the application may not have been written to properly handle the graphics switch. In order to prevent the application from crashing, which may result in a loss of data, the system blocks the graphics switch until the application is closed.
This tip only applies to ThinkPad T410s systems with nVidia Switchable Graphics hardware and in Switchable Graphics mode. This requires:
- Microsoft Windows Windows 7 (either 32-bit or 64-bit).
- BIOS Graphics Device is set to Switchable Graphics.
To resolve this problem, the application which is preventing the switch needs to be closed or explicitly added to the Approved List. This is a list that is stored in the registry, and tells the graphics driver that the application can properly handle the graphics switch. The registry location is:
The executable name of the application needs to be added to the registry value, which is just a list of filenames separated by a comma and a space. Alternatively, some applications can be configured to not use hardware acceleration (no DirectX or OpenGL functions are used). If so, this option would be somewhere in the application's settings and preferences menus.