Sun Microsystems SPARC T5220 - Manual (Page 22)

20 Sun SPARC Enterprise T5120 and T5220 Server Architecture Sun Microsystems, Inc.
The motherboard interconnect for these systems has been greatly simplified. 12-volt
power is distributed to the motherboard through a pair of metal bus bars, connected to
a Power Distribution Board (PDB). A single flex-circuit connector routes all critical power
control and DVD drive signaling over to the PDB. One or two mini-SAS cables connect
the motherboard to the disk drive backplane, providing data access to the system hard
drives.
Memory Subsystem
In Sun SPARC Enterprise T5120 and T5220 servers, the UltraSPARC T2 processor’s on-chip
memory controllers communicate directly to FBDIMM memory through high-speed
serial links. The four dual-channel FBDIMM memory controllers can transfer data at an
aggregate rate of 32 giga-transfers per second. Sixteen memory socket locations
provide sufficient board space for two rows of 667 MHz FBDIMMs per channel.
I/O Subsystem
The UltraSPARC T2 processor incorporates a single, 8-lane (x8) PCI Express port capable
of operating at 4 GB/second bidirectionally. This port natively interfaces to the I/O
devices through a series of PLX technology PCI Express expander chips, connecting
either to PCI Express card slots, or to bridge devices that interface with PCI Express,
such as those listed below.
• Disk Controller — Disk control is managed by a single LSI Logic SAS1068E SAS
controller chip that interfaces to a four-lane (x4) PCI Express port. RAID levels 0 and 1
are provided as standard.
• Dual GBE — Two x4 PCI Express ports connect to two Intel Ophir dual Gb Ethernet
chips, providing four 10/100/1000 Mbps Ethernet interfaces on the rear of each
chassis.
• USB and DVD — A single-lane PCI Express port connects to a PLX PEX8111 PCI bridge
device. A second bridge chip converts the 32-bit 33MHz PCI bus into multiple USB 2.0
ports. The system’s USB interconnect is driven from those ports. In addition, the DVD
is driven from a further bridge chip that interfaces one of the USB ports to IDE format.
To minimize cabling and increase reliability, a variety of smaller boards and riser cards
are deployed, appropriate to each chassis. These infrastructure boards serve various
functions in the Sun SPARC Enterprise T5120 and T5220 servers.
• Power distribution boards distribute system power from the dual power supplies to
the motherboard and to the disk backplane (via a connector board)
• Connector boards eliminate the need for many discrete cables, providing a direct card
plug-in interconnect to distribute control and most data signals to the disk
backplane, fan boards, and the PDB.