Question about integrated graphics

[imac5k]

It is my understanding that most CPU's nowadays have integrated GPU's built in. That being said, I know apple relies on the integrated GPU for lower end computers, and for energy reasons as is the case with the 15in rMBP. But what about in the iMacs with discrete graphics cards only? Does the integrated GPU exist and is not used? It seems like a waste to have it there and not use it for anything. Or I could be completely mistaken and if that is the case, I'd like someone to explain where I went wrong. Thanks.

 

[chscag]

All current iMac computers have a discrete (separate) graphics processor and individual VRAM. The integrated graphic chipsets made by Intel which Apple uses in their portable computers "borrow" memory from the system memory which is installed. You can find out more about the integrated graphic chipsets by visiting the Intel site. And, by the way, some MacBook Pros have both an integrated graphics chipset for low power use and a separate discrete graphics processor with its own VRAM which would be used for graphic intensive applications and games.