How GPUs Work Together ?

[Satnam Sync]

Experts please tell me, that if we have 2 GPUs available i.e., motherboard integrated and Processor integrated graphic then both will work simultaneously or a major GPU i.e, Processor's GPU will work only......?
Am not considering a graphics card.

 

[sourodip]

well with the recent launching of amd's APU they have their gpu integrated in the processor nad with certain boards like A55M it is not possible for the two GPU's to work together in the form of hybrid crossfire unless u add one discrete gpu for the two gpu's(the APU and the discrete one) to work in dual mode