I have a desktop computer equipped with 2 graphics processors:
- Intel HD Graphics (Integrated): output = VGA
- NVIDIA GeForce GTX (Dedicated): output = DVI
I used to plug my monitor via the VGA port (because I didn't have DVI cable), however because the video gets rendered via Intel GPU, the second graphics processor (NVIDIA) doesn't get detected by the operating system (not appearing in the list of connected devices within the
Device Manager system utility).
And the problem disappears after plugging the monitor to the DVI interface of the dedicated card.
This sounds to me weird, since the card is plugged to the motherboard via AGP bus, that provides the required power supply from the motherboard. I don't know why the DVI connection is required, for the expansion card in order to make it work.
The OS is Windows 10 with all the device drivers pre-installed (including the dedicated graphics card driver); I assumed that it was a device driver compatibility issue, so I managed to re-install the display drivers matching the card model from NVIDIA website, taking care of OS compatibility. Yet, without a solution.
Why the OS fails to detect the Graphics card when the monitor is not plugged in?