NEC 1080Xd manual Selecting a Slot, Board Installation and Operating Frequencies

Selecting a Slot

Installation can impact the operating frequency of a board. Note the following information before selecting a PCI slot:

Note: See Figure 5-2 for Core Module slot locations or Figure 5-4 for PCIX Unit slot locations. These figures slot frequencies and bus groups.

The actual operating frequency of a board is lower than the highest specified operating frequency when the following conditions occur:

!More than two PCI boards are installed in the same bus group (does not apply to PCI-X boards)

!Boards with different operating frequencies are installed in the same bus group.

PCI 33-MHz is the highest specified operating frequency for the following boards:

!Basic I/O Board

!SCSI Card DAT device in the server chassis.

See Table 5-3. for information about how installation in a particular slot and with other boards can determine the operating frequency of boards within the bus group.

Table 5-3. Board Installation and Operating Frequencies

Board Type	Installation	Operating Frequency
PCI 33-MHz	Installed within the same bus group with other	Operating frequency of all boards
board	boards having a higher operating frequency than	is 33 MHz.
	33-MHz
PCI 66-MHz	Up to 2 boards installed within the same bus group	Operating frequency of boards is
board		66 MHz.
	Three or more boards installed within the same bus	Operating frequency of all boards
	group	is 33 MHz.
PCI-X 66-MHz	All slots within the same bus group are occupied	Operating frequency of all boards
board	with PCI-X 66-MHz boards	is 66-MHz.
		Operating frequency does not
		decrease as in PCI examples.
PCI-X 133-MHz	Installed in 66-MHz slot	Operating frequency is limited to
board		66 MHz; installation in 66-MHz
		slot is not recommended.

5-6 I/O Board Installation