Dell PowerEdge 2650 - Manual (Page 50)

Replacing the Expansion-Card Cage
1. With the expansion-card cage lever in the upright position, lower the cage into the chassis until it is aligned with the tabs on the chassis side wall (see
Figure 6 -3 ).
2. Rotate the expansion-card cage lever down until the handle is flush with the top of the cage, and the cage is secured in the chassis (see Figure 6 -3 ).
3. Reconnect all expansion-card cables.
4. Replace the cover (see " Replacing the Cover " in "Troubleshooting Your System").
Expansion Cards
The system includes three expansion slots. The expansion cards are installed on the system's riser board (see Figure A -4 to identify the expansion slots).
Expansion Card Installation Guidelines
You can install expansion cards of different operating speeds on the same bus; however, the bus will operate at the slowest operating speed of the cards on
that bus. For example, if one card on the bus has an operating speed of 66 MHz and the other card has an operating speed of 100 MHz, the bus will only
operate at 66 MHz.
To identify expansion slots and PCI buses, see Figure A -4 . Table 6 -1 lists the PCI bus and operating speed for each expansion-card slot.
PCI Bus Scan Order
The system's BIOS scans and numbers PCI buses and devices during startup. Expansion slots are scanned according to the host bus ordering, not by the slot
numbers. See
Table 6 -2 for the order in which the expansion slots and embedded PCI devices are scanned. Figure A -4 provides a diagram of buses and
expansion slots.
An additional factor affects the assignment of PCI bus numbers: an expansion card may have its own PCI bridge chip which requires the assignment of a bus
number for the card as well as one for the bridge. A particular expansion card may have two PCI bridge chips which would result in three sequential PCI bus
numbers all assigned in the same expansion slot.
If you install expansion cards, you may have some difficulty in directly determining the bus number of a controller on a particular expansion card. However, the
PCI bus scan order listed in
Table 6 -2 can help determine the relative numbering of PCI buses within the expansion slots. For example, a PCI controller
residing in expansion slot 3 will never have a lower bus number than one in slot 2 because slot 2 precedes slot 3 in the scan order.
NOTICE: See "Protecting Against Electrostatic Discharge" in the safety instructions in your System Information document.
Table 6-1. Expansion Slot Speeds
Slot Bus Operating Speed
1 1 33, 66, or 100 MHz
2 1 l Slot 1 is not empty — 33, 66, or 100 MHz
l Slot 1 is empty — 33, 66, 100, or 133 MHz
3 2 33, 66, 100, or 133 MHz
NOTE: If you are using expansion cards of different operating speeds, you should install the fastest card in slot 3 and the slowest card in slot 1.