Hardware Reference
In-Depth Information
The PCI specification identifies three board configurations, each designed for a specific
type of system with specific power requirements; each specification has a 32-bit version
and a longer 64-bit version. The 5V specification is for stationary computer systems (us-
ing PCI 2.2 or earlier versions), the 3.3V specification is for portable systems (also sup-
ported by PCI 2.3), and the universal specification is for motherboards and cards that
work in either type of system. 64-bit versions of the 5V and universal PCI slots are found
primarily on server motherboards. The PCI-X 2.0 specifications for 266 and 533 versions
support 3.3V and 1.5V signaling; this corresponds to PCI version 2.3, which supports
3.3V signaling.
Note
You can find pinouts for the 5V, 3.3V, and universal PCI slots on the disc in the Technical
Reference section.
Figure4.41
comparesthe32-bitand64-bitversionsofthestandard5VPCIslottoa64-bit
universal PCI slot.
Figure 4.42
shows how the connector on a 64-bit universal PCI card
compares to the 64-bit universal PCI slot.
Figure 4.41
A 32-bit 33MHz PCI slot (top) compared to a 64-bit 33MHz PCI slot (center) and a 64-bit
universal PCI slot that runs at 66MHz (bottom).
