As the answer to my question may differ depending on the specific hardware of a computer, I will limit my discussion to common PCs that we use everyday. The reason for asking this question is to try to solve my laptop problem (click to see).
My laptop has an Intel HD 3000 GPU integrated into my i7-CPU, and a discrete Nvidia graphics card with its own memory. When it enters BIOS, I will see a setup screen that allows me to configure hardware settings using the keyboard.
My question is, for the BIOS to generate the signal for the monitor, are the graphics card(s) involved at all? If yes, which one is used?
Most of the time, the integrated Intel GPU was used by Win7, because GPU-Z shows that the memory usage and load of the Nvidia card is always zero (Unless some 3D programs are running, or any application is purposely opened with the discrete GPU). What I'm not sure about is the BIOS screen output.
Edit 1 From wikipedia I found this:
"The modern Video BIOS does not support all the functions of the video card, being only sufficient to identify and initialize the card to display one of a few frame buffer or text display modes. It does not support YUV to RGB translation, video scaling, pixel copying, compositing or any of the multitude of other 2D and 3D features of the video card."