AGP was a modified PCI bus making it a high speed point-to-point PCI connection. It was only ever intended to connect a single graphics controller so for years

AGP was a modified PCI bus making it a high speed point-to-point PCI connection. It was only ever intended to connect a single graphics controller so for years we had only one AGP port (They later hacked more than one slot/chip but PCIe thankfully happened). The idea was the higher bandwidth could allow the graphics chip to use main memory for graphics but that access was much much slower than the on-board RAM on the . Plus you know, your CPU and hence, OS And programs also needed to access that memory. I am pretty sure that idea was quickly abandoned after the i740 flopped.