I have Dell XPS L502x and I bought which has 2GB NVIDIA GeForce GT 540M Graphics card
But it runs on Intel Graphics
How to use Nvidia Graphics instead Intel Graphics?
Basically your system is not using the Nvidia card because it doesn't need to. If you were to start watching a HD movie or playing a game then it would switch to using the Nvidia hardware, the fact of the matter is that you're not doing anything that needs the Nvidia card to kick in so your laptop is saving power by turning off the Nvidia card and using the integrated graphics instead.
You might need to configure NVidia Optimus to use dedicated NVidia graphics. Usually optimus will automatically switch when dedicated graphics are needed.
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