General Description 2-111 Power supply unit2 Mother board3 Cooling fan (factory-installed)3-1 PCI (FAN5)3-2 Front (FAN7)3-3 Rear (FAN1)4 Redundant fanFront (FAN4)5 DIMMs6 CPU heat sink5-1 CPU 15-2 CPU 2 (additional)7 Optical disk drive8 5.25-inch device bayAn optical disk drive is factory-installed in the bottom slot.9 Hard disk drive bay10 PCI guide rail11 Additional battery bracket