All systems use the same board types, with the exception of load boards and filler panels.
The CPU/Memory+ board supports up to two UltraSPARC II modules and 16 SIMM slots.
The SBus+ I/O board includes two SYSIO ASICs that provide two SBuses: one for two plug-in SBus cards and two GBIC (100 MB/sec Fibre Channel) interfaces, and one for one plug-in SBus card and the onboard devices (10/100 Mbit TPE and Single-ended Fast/Wide SCSI).
The Graphics+ I/O board includes one SYSIO ASIC that provides a single SBus for two plug-in SBus cards, two GBIC (100 MB/sec Fibre Channel) interfaces, and the onboard devices (10/100 Mbit TPE and Single-ended Fast/Wide SCSI).
The PCI+ I/O board has two PCI bus connectors, each of which can accommodate a PCI riser card. Each riser card accommodates one PCI short card. In addition, onboard devices provide Fast Ethernet (10/100 Mbit) and Fast/Wide SCSI interfacing.
In the Enterprise 6500 system, empty board slots require load boards (part number 501-3142) to reduce the possibility of RFI generation. The Enterprise 5500 and 4500 systems use filler panels (part number 540-2592).