Compaq EN Series 2.4 SYSTEM ARCHITECTURE

Chapter 2 System Overview
Compaq Deskpro EN Series of Personal Computers
Desktop and Minitower Form Factors
Third Edition – September 1998
2-10
2.4 SYSTEM ARCHITECTURE
The Compaq Deskpro EN Series of Personal Computers is based on an Intel Pentium II processor
matched with the Intel 440BX AGPset. The basic architecture (Figure 2-8), uses three main
buses: the Host bus, the Peripheral Component Interconnect (PCI) bus, and the Industry Standard
Architecture (ISA ) bu s.
The Host and memory buses provide high performance support for CPU, cache and system
memory accesses, and operate at 66 or 100 MHz, depending on the speed of the microprocessor.
The PCI bus provides support for the UATA controllers, USB ports, and PCI expansion devices.
The PCI bus operates at 33 MHz. Th is system also includes an Acceler a t ed Graphics Port (AGP)
slot for an AGP graphics card. T h e AGP bus is closely associated with the PCI bus but operates at
66 MHz and allows data pipelining, sideband addressing, and frame mode transfers for increased
3D graphics performance.
The ISA bus provides a standard 8-MHz interface for the input/output (I/O) devices such as the
keyboard, diskette drive, serial and parallel interfaces, as well as the addition of 16- or 8-bit
expansion devices.
The north and south bridge functions are provided by the 440BX AGPset designed to compliment
the processor. The support chipset also provides memory controller and data buffering functions
as well as bus control and arbitration functions.
The I/O interfaces and diskette drive controller are integrated into the PC87307 I/O Controller.
This component also includes the real time clock and battery-backed configuration memory
(CMOS).
Table 2-1 lists differences between system models:
Table 2–1. Model Differences
Table 2-1.
Model Differences
Model 3200 Model 4300 Mod el 6400 Model 9100
Form Factor DT/MT DT/MT DT/MTMT
CPU Speed (MHz) 266/300/333 333/350/400 300/333/350/400 400/450
Host Bus Speed (MHz) 66 66/100/100 66/66/100/100 100
Hard Drive 3.2 GB UATA 4.3 GB SCSI 6.4 GB UATA 9.1 GB SCSI
System Memory:
Standard
Maximum installable 16/32 MB SDRAM 384 MB 32/64 MB E CC 384 MB 32/64 MB SDRAM 384 MB 64 MB ECC 384 MB
Graphics Controller ATI RAGE PRO
Turbo
AGP 1X Card
ATI RAGE PRO
Turbo
AGP 2X Card
ATI RAGE PRO
Turbo
AGP 1X/2X Card
ATI RAGE PRO
Turbo
AGP 2X Card
NOTE: Only BTO configurations shown.
The following subsections provide a description of the key functions and subsystems.