USB Enhanced and Integrated Ethernet Service Manual

System Overview 1-1
Chapter 1
System Overview
T
his service manual covers the Dell
®
OptiPlex
®
GXpro high-speed, upgrad-
able desktop systems, which use the Intel
®
Pentium
®
Pro family of
microprocessors. These Dell systems incorporate the high-performance PCI
local bus as well as the ISA expansion bus. These buses are built into the system
board, which also integrates a 3.3-V Pentium Pro microprocessor and all other
elements of the basic computer system.
The Pentium Pro microprocessor contains a built-in clock multiplier circuit,
which increases the microprocessor’s internal operating frequency to a multiple
of the system clock frequency. The microprocessors for each of these systems
and their operating frequencies are as follows:
•
Dell OptiPlex GXpro 180 systems — 180 MHz derived from a system clock
frequency of 60 MHz
•
Dell OptiPlex GXpro 200 systems — 200 MHz derived from a system clock
frequency of 66 MHz
Dell OptiPlex GXpro systems contain either an integrated 10-Mbps or
10/100-Mbps 3Com
®
NIC, both of which are covered in this document.