The rationale behind NVIDIA's decision is that while we need a super powerful graphics card in games, the computer system is actually not going to need all that graphical power while it is running desktop applications. In many cases, enthusiasts are using computers for web browsing, working, and running non-graphically intensive applications. It would be wasteful to have a powerful 3D graphics card sitting idle during these applications, wasting precious electrical power. Thus, by incorporating mGPU and combining it with NVIDIA's "Hybrid power", the computer is able to reduce the power usage (and energy bill) by switching off the discrete graphics card and using only the integrated graphics for low-demand applications. When the demand for graphic power increases, the dedicated graphic card will then kick in.



Link: Bjorn3D