As a general rule, all board slots in the card cage are interchangeable. However, the requirements and limitations in the following sections apply when you install boards.
Install CPU/Memory+ boards at the front of the system, starting with the top slot (slot 0). If you reserve the rear slots for I/O+ boards, I/O cable attachments will be made easier.
After the front slots are filled, you may add CPU/Memory+ boards at the rear of the system, below the I/O+ boards.
Requirement-An I/O+ board must always be in slot 1. This is the only slot that allows access internally to the internal SCSI devices (tape and CD-ROM drives.)
Install I/O+ boards at the rear of the system to facilitate I/O cable attachments.
If you require additional slots, you may use those at the front of the card cage, preferably below the CPU/Memory+ boards.
Maximum-Up to four graphics (UPA) cards are supported in a system.
Requirement-The I/O+ board in slot 1 of any Enterprise server must be terminated because it connects to the media tray.
An I/O+ board in a slot other than slot 1 does not require termination if no devices connect to the SCSI bus on that board.
Maximum-The Enterprise 6500 system supports up to two Disk boards. (Disk boards are supported only in slots 14 and 15. Slot 15 must be used when installing only one Disk board.)
Maximum-The Enterprise 5500 and 4500 systems support up to four disk boards.
The disk board has a capacity of two disk drives. In addition to the three status LEDs found on other types of boards, the disk board has two LEDs to show the status of the individual disk drives. LEDs 1 and 2 represent drives 0 and 1, respectively.
Requirement-The fans in the power/cooling modules (PCMs) provide cooling air only for the two adjacent board slots. Do not install a board in a slot that is not cooled by a PCM.
Requirement-You must fill all empty slots (board slots and power supply slots) to avoid loss of cooling air to the active boards. For further information on this subject, see "Filler Panels and Load Boards".
Under some circumstances, you may remove a power/cooling module from an active system for a short time. However, if the boards in the adjacent slots create large quantities of heat, it is safer to halt and power off the system first.
Requirement-All empty board slots must be filled with filler panels or load boards.
Requirement-For Enterprise 6500 systems, use load boards. A load board (part number 501-3142) is identified by the presence of connector sockets and passive circuitry, which reduces electrical noise at the center plane. Do not substitute filler panels, which do not have load circuits.
Requirement-For Enterprise 5500 and 4500 systems, use filler panels (part number 540-2592).
Requirement-Filler panels are required for all unused PCM bays.