What is PCI Express?

Definition: PCI Express is a expansion slot that is becoming the new standard for high speed internal devices for computers such as graphics cards. PCI Express slots come in several types defined by the number of lanes the slot has to communicate with described as x1, x4, x8, x12, x16 and x32. The most commonly found types inside current computers are the x1 and x16. Graphics cards are available that will run on both x1 and x16 cards. However, all high performance graphics cards use the x16 slot.