Dell OptiPlex G1 Service Manual page 12

1-2 Dell OptiPlex G1 Managed PC Systems Service Manual
The three OptiPlex G1 chassis configurations differ primarily in the following
expansion features:
Number of expansion slots available for PCI/ISA expansion cards
Number of available internal drive bays for EIDE drives
Number of available external drive bays for diskette, CD-ROM, or tape
drives
Physical size and power supply types (the midsize and mini tower systems
use the same power supply)
Due to the physical differences in the three chassis configurations, a separate
parts removal and replacement chapter (Chapters 4 through 6) is provided for
each chassis type.
All three chassis configurations have the following similarities:
Same system board
Identical operational characteristics (same BIOS, POST, memory,
microprocessor, external I/O ports, and so on)
Identical diagnostics, diagnostic beep codes, and diagnostic-screen error
messages (see Chapters 1 through 3 and Appendix A)
The features described in the following subsections are common to all chassis
configurations.
All OptiPlex G1 systems incorporate the Pentium II microprocessor for
improved operating speeds and overall performance. Some of the major
enhancement features of the Pentium II microprocessor include internal 16-KB
data and instruction caches, internal math coprocessor, and the MMX instruc-
tion set for high performance in complex multimedia and communications
environments. The Pentium II microprocessor also uses a technique called
"single instruction, multiple data" (SIMD), which permits processing data ele-
ments in parallel for additional system performance enhancement.
The microprocessor is physically located in a single-edge contact (SEC)
cartridge/heat sink assembly on the system board for ease of upgrading when
faster processors become available. Contact Dell Computer Corporation for
information about Dell-supported microprocessor upgrades.