I am working with four displays and both external and internal GPU enabled (IGFX enabled). Three of them are connected to external GPU and the other is connected to motherboard. In graphics control panel, I see that each display is allocated to specific GPU. In fact, the previous QnA says both CPU and GPU contribute to the rendering process for the pixels displayed. However, I use two GPU and sometimes I put a window among multiple displays. In this case, I am wondering which GPU or CPU are actually working on which drawing region, including hidden part of the window outside the displayed region.
I know that the basic window class in Windows 10 use GDI+ and some app or games use DirectX or OpenGL library. Is there a difference between them in terms of rendering unit? According to my friend, the reference point of rendering would be the top-left corner point (I'm not sure but I want to know the truth).
The following image shows my configuration
Display #1, #2, #3: connected to external GPU (NVIDIA GTX 1060)
Display #4: connected to motherboard graphics port (Intel i7-8700's internal GPU)
The following examples show several possibilities for the location of a window (red rectangle). In each case, I want to know which processor calculates which partition.
Case 1:
This case is obvious that CPU and external GPU (GTX 1060) work for the whole window region.
Case 2:
Case 3:
Case 4:
Case 5:
