I have a Lenovo T420 laptop (Windows 10) with:
- integrated Intel HD Graphics 3000, latest drivers (18.104.22.16829)
- nVidia NVS 4200M, latest nVidia drivers from Lenovo website (10.18.13.5445)
I also have LCD monitor that has maximum resolution of 1920 x 1200 px. I would like to force using the Intel graphic card while the monitor is connected through Display Port and no application is running. When a graphic demanding application starts it can switch to the discrete nVidia graphics based on Optimus application settings. (Essentially I want the reverse of Use Nvidia optimus card for HDMI output with DisplayPort)
From Intel hardware specification the internal Intel HD Graphics 3000 display adapter should be capable of a maximum resolution 2560 x 1600 px regardless the connector (DisplayPort, HDMI or VGA), so it should't be a problem.
But there is a problem as it always runs from external nVidia graphic card even when no applications are running while connected with Display Port cable. When I swap the DisplayPort cable for VGA cable it runs from internal graphic card as intended (on the same resolution).
If I disable the external graphic card in BIOS or Windows Device Manager so I force it to use the internal graphic card, it sends no signal to the monitor.
How can I enable DisplayPort for internal Intel graphics card?