If you are using Windows and looking for a freeware app to monitor graphics card, then you should be trying out GPU Shark. GPU Shark is a simple GPU monitoring tool (based on ZoomGPU). It is a portable app for Windows which can be used to fetch details for NVIDIA GeForce and AMD/ATI Radeon graphics cards. Since it does not require any installation, you can simply run the tool and get all the details.
Once you run the app it can display the clock speeds (GPU core, memory), fillrates, performance states (or PStates), GPU fan speed, GPU/memory/MCU usage and power consumption (NVIDIA). Some of the options are based on the GPU of your PC.
The app has two options, one is a simple view where you get minimal options while the second option is detailed mode. In simplified mode (default), only the essential hardware information is displayed: graphics card name, temperatures (GPU, PCB) and clocks (GPU, memory, and shader).The detailed more fetches you more detailed information and you can also copy the GPU data to the clipboard.
The app is available for all versions of Windows and you can download it from the link below.