TYAN TOMCAT I915 User Manual page 41

Tomcat i915 S5120
PCI Express on the other hand implements a serial, point-to-point type interconnect for
communication between two devices. Multiple PCI Express devices are interconnected via the
use of switches, which means one can practically connect a large number of devices together
in a system. A point-to-point interconnect implies limited electrical load on the link allowing
transmission and reception frequencies to scale to much higher numbers. Currently PCI
Express transmission and reception data rate is 2.5 Gbits/sec. A serial interconnect between
two devices results in fewer pins per device package, which reduces PCI Express chip and
board design cost and reduces board design complexity. PCI Express performance is also
highly scalable. This is achieved by implementing scalable numbers for pins and signal lanes
per interconnect based on communication performance requirements for that interconnect.
However, PCI Express is software backwards compatible with existing PCI systems. In fact, a
PCI Express system will boot an existing OS with no changes to current drivers and
application programs. Even PCI/ACPI power management software will still run.
PCI Express Ports 1-4
When enabled, the BIOS checks these ports to detect and activate the PCI devices connected
to them.
When set to Auto, the BIOS auto determines whether to enable or disable them, depending on
whether PCI devices have been connected.
•
Auto
•
Enabled
•
Disabled
PCI-E Compliance Mode
This BIOS option determines compatibility between PCI-Express specification v1.0 and PCI-
Express specification v1.0a.
•
V1.0a
•
V1.0
PEG/Onchip VGA Control
This option lets the BIOS choose the VGA controller. PEG or Portable Embedded GUI is a
hardware independent set of GUI classes to construct visual displays for embedded systems.
If you do have PEG installed, then the BIOS can use PEG instead of the Onchip VGA
controller.
The default mode is Auto in which the BIOS determines the correct VGA controller to use.
•
Auto
•
Onchip VGA
•
PEG Port
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Chapter 3: BIOS Setup