Datasheet

Identifying Motherboards 41
AGP (Accelerated Graphics Port)
As systems got faster, PC game players wanted games that had better graphics, more real-
ism, and more speed. However, as the computers got faster, the video technology couldn’t
seem to keep up, even with the PCI bus. The AGP bus was developed to meet this need.
The AGP slot is usually brown, and there is only one. It’s a 32-bit or 64-bit bus, and it
runs very fast (66MHz or faster). It’s used exclusively for the video card. If you use a PCI
video card, the AGP slot remains empty. See Figure 1.16.
FIGURE 1.16 An AGP slot on a motherboard
AGP slot
PCIE (PCI Express)
PCI Express (PCIE , PCI-E, or PCIe) uses a network of serial interconnects that operate at
high speed. It’s based on the PCI system; most existing systems can be easily converted to
PCIE. Intended as a replacement for AGP and PCI, PCIE has the capability of being faster
than AGP, while maintaining the flexibility of PCI. There are currently six different speed
levels and they correspond to AGP speeds: 1X, 2X, 4X, 8X, 16X, and 32X.
AMR and CNR
Audio Modem Riser (AMR) was originally created to speed manufacturing (and certifica-
tion) by separating the analog circuitry (modem and analog audio) onto its own card. Over
time, this has been replaced by Communications Network Riser (CNR), which includes
the capabilities of AMR and allows the motherboard chipset to be designed with additional
integrated features.
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