I have some questions about Multi-GPU and the WGL_nv_gpu_affinity_extension:
I read that the default behaviour for a system with multiple graphics boards is, that all OpenGL commands you send to a “conventionally” created WGLRC (without affinity mask) are executed on all installed graphics boards.
Does that mean, if i create a window (and rendering context from that window) on a monitor connected to GPU1, I can drag that window to a monitor on GPU2 and the OpenGL content is still updated (because all opengl resources and commands are directed to all gpus in the system)?
In contrast, I also heard that if I create a window and rendering context on a monitor connected to GPU1, all opengl commands are automatically directed ONLY to GPU1. Is that really true?
And if so, what is the point of the GPU affinity extension?
As far as I understand the affinity concept right, the aim is to being able to direct opengl commands to a specific list of “affinity” gpus in the system. A concept that would be redundant if the above sentence was true. Is that right?
And finally i want to ask, if there are some known issues with the WGL_nv_gpu_affinity_extension and Windows 7 64bit. I wrote a little program according to the extension spec, to target rendering to either (and both) of the QUADRO FX3800 boards in my system, which doesn’t work properly.
Thanks a lot!