Dell OptiPlex GX1 Service Manual page 27

The mini tower computers have seven expansion-card slots. The riser board
has four ISA expansion-card connectors and five PCI expansion-card connec-
tors. Two PCI expansion-card connectors share expansion-card slots with two
ISA connectors, resulting in a total of seven expansion-card slots (see
Figure 1-11). The riser board is active, incorporating PCI-to-PCI bridging.
The mini tower riser board includes the P1 connector (for connecting the NIC
to the riser board cable) and an LED. If the LED is on, the riser board is receiv-
ing power; if off, the riser board is not receiving power.
LED
PCI5
PCI4
PCI3
PCI2
PCI1
The system board has various accommodations for system upgrades
including:
Microprocessor upgrade
Main memory expansion
Video memory expansion
These upgrades are summarized in the following subsections, and installation
procedures are provided for the various chassis configurations in Chapters 4, 5,
6, and 7 .
On the OptiPlex GX1 and OptiPlex NX1 systems, the microprocessor and sec-
ondary L2 cache memory are implemented in an SEC cartridge/heat sink
assembly. Upgrade to a higher-performance microprocessor is accomplished
by snapping out the old assembly and installing an upgrade assembly as
higher-performance microprocessors become available.

ISA4
ISA3
ISA2
ISA1
P1 connector
HDLED
connector
System Overview 1-15