HP Proliant DL580 - Server Specifications; Environmental Specifications; Physical and Electrical Specifications

122 HP ProLiant DL580 Generation 3 Server Maintenance and Service Guide
SCSI simplex mode
In the PCI simplex cabling configuration, an optional PCI array controller
controls up to four hard drives through one SCSI bus.
SCSI duplex mode
In the PCI duplex cabling configuration, an optional PCI array controller controls
up to four hard drives through two SCSI buses. Each bus controls two hard
drives.