If your PC is using CPU instead of GPU, check your cable connections. Use the fixes provided in this article to resolve this issue.

While gaming using Steam’s Big Picture Mode can be extremely helpful, as it offers a slick, console-like experience, it occasionally defaults to using your integrated GPU instead of your dedicated GPU ...

Whether you're looking to download a GPU-specific driver, trying to determine whether you'll be able to play a new game at a reasonable frame rate, or checking the specs on an unfamiliar PC, knowing ...