How can I see which GPU is being used?

The framerate is very low for me (under 15fps). I think it is using the Intel GPU instead of my NVidia GeForce. How can I verify which it’s using?

If your using Windows 10 Redirect Notice

If your using an older version of Windows GPU Shark - lightweight and free GPU monitoring tool for NVIDIA GeForce and AMD/ATI Radeon graphics cards | oZone3D.Net

Apparently I found out my GPU isn’t supported with it for some reason so it won’t display GPU information. However I just got a program called “TechPowerUp GPU-Z” which is working well for me now. Thanks Anyways!