I/O Technologies; Pci Express Technology; Hp Smart Array And Sas/Sata Technology - HP ProLiant DL160se - G6 Server Introduction Manual

I/O technologies

ProLiant 100-series G6 servers incorporate PCI Express, Serial-Attached SCSI (SAS), and Serial ATA
(SATA) I/O technologies. PCI Express lets administrators add expansion cards with various
capabilities to the system. SAS is a serial communication protocol for direct-attached storage devices
such as SAS and SATA hard drives.

PCI Express technology

All ProLiant G6 servers support the PCIe 2.0 specification. PCIe 2.0 has a per-lane signaling rate of
5 Gb/s which is double the per-lane signaling rate of PCIe 1.0 (Figure 4).
Figure 4. PCIe data transfer rates
Lane 1 Send Lane 1 Send
Lane 1 Receive Lane 1 Receive
Source Source
n n
Lane Lane Send Send
Lane Lane n n Receive Receive
PCIe 2.0 is completely backward compatible with PCIe 1.0. A PCIe 2.0 device can be used in a
PCIe 1.0 slot and a PCIe 1.0 device can be used in a PCIe 2.0 slot. Table 3 shows the level of
interoperability between PCIe cards and PCIe slots.
Table 3. PCIe device interoperability
PCIe x4 Connector
device type x4 Link
x4 card x4 operation
x8 card Not allowed
x16 card Not allowed

HP Smart Array and SAS/SATA technology

The newest serial PCIe 2.0-capable Smart Array controllers use SAS technology, a point-to-point
architecture in which each device connects directly to a SAS port rather than sharing a common bus
as with parallel SCSI devices. Point-to-point links increase data throughput and improve the ability to
locate and fix disk failures. More importantly, SAS architecture solves the parallel SCSI problems of
clock skew and signal degradation at higher signaling rates.
3 For more information about SAS technology, refer to the HP technology brief titled "Serial Attached SCSI storage technology"
available at http://h20000.www2.hp.com/bc/docs/support/SupportManual/c01613420/c01613420.pdf .
Max. bandwidth
(Send or receive)
Link
size PCIe 1.0
x1 250 MB/s
Target Target
x4 1 GB/s
x8 2 GB/s
x16 4 GB/s
x8 Connector x8 Connector
x4 Link x8 Link
x4 operation x4 operation
x4 operation x8 operation
Not allowed Not allowed
(Send and receive)
PCIe 2.0 PCIe 1.0
500 MB/s 500 MB/s
2 GB/s 2 GB/s
4 GB/s 4 GB/s
8 GB/s 8 GB/s
x16 Connector
x8 Link
x4 operation
x8 operation
x8 operation
3
Total
PCIe 2.0
1 GB/s
4 GB/s
8 GB/s
16 GB/s
x16 Connector
x16 Link
x4 operation
x8 operation
x16 operation
11