Physical Differences PCI Express [PCI-E] VS AGP VS PCI

Currently, the most common use for PCI Express is Video. There are physical differences among the cards.The connector on PCI Express video cards will always start out with a small piece not directly joined with the rest of the slot, and then a notched piece not directly joined with the rest of the slot. This notch goes into the 1x portion of the 16x slot. The characteristic notch makes it easy to tell the difference between PCI-E (PCI Express) and an AGP Video card. As you can imagine, a PCI Express Video card will not fit into an AGP card slot, and an AGP Video card will not fit into a 16x PCI Express card slot.Another physical difference between PCI Express Cards, AGP, and PCI is the distance among the card's bracket and the start of the connector. On PCI Express cards, there is very little distance between the metal bracket and the start of the connector. On both PCI and AGP the distance is much longer.PCI Express 1x / 4x cards also have the physical difference in regard to bracket distance. They are both a good deal smaller than standard PCI. At this time this type of card is still quite rare so at this point there is little chance of confusing them with something else. The PCI Express 1x connector does however bare some minor resemblance to an AMR slot, so it is important not to confuse the two. No motherboard on the market today currently has both the older AMR slot and PCI Express.