Apple MacBook Pro 15-inch Laptop

Also, earlier when the previous Core series of processors were used, the memory controller was on the North Bridge of the motherboard chipset. Now, memory controllers are integrated into the CPUs such as the new Core i5 and i7 processors. Since, Nvidia is not licensed to make chipsets for any Intel CPU which has a built in memory controller, they have to use Intel chipsets, which have comparatively inferior onboard graphics. Now, since Apple could not kill the feature of toggling between onboard and discrete graphics, what they've done is that, they've integrated a separate discrete Nvidia GPU on the motherboard alongside the onboard Intel GPU.

The 13-inch models have stuck with previous Intel Core 2 Duo CPUs, mainly because even if they go with an Intel GPU but with an Intel Core i5 processor, the power consumption will increase, hence draining battery resources. But, with Intel coming up with more powerful and energy-efficient CPUs, it’s a matter of time before we can get smaller MacBooks Pro laptops with refreshed hardware.
Previously, if you wanted to toggle between GPUs, you had to log out and log back in. But, now this happens in real time. The machine detects your work load and switch on/off the discrete graphics. This might sound familiar, because Nvidia offers a similar technology called Opitimus, but this is different.