Storage Technologies; Serial Attached Scsi (Sas); Small Form Factor (Sff) Hard Drives - HP DL585 - ProLiant - G2 Technology Brief

Table 2. Preferred order for populating PCI Express expansion slots in the ProLiant DL585 G2 server
Installation Slot
sequence
First 7
Second 5
Third 8
Fourth 3
Fifth 4
Sixth 9
Seventh 6

Storage technologies

The DL585 G2 has an updated disk subsystem and includes the Smart Array SAS P400 Controller.

Serial Attached SCSI (SAS)

The peak data transfer rate for the current generation of SAS drives is 3 gigabits per second in full
duplex mode. In a serial system, the devices do not share a common bus, and each device can take
full advantage of the bandwidth available to it. The SAS backplane connector is compatible with
SATA drives, and the chipset on a SAS controller can communicate with SATA drives. This enables
administrators to store data that needs to be available at a high performance standard on SAS disk
drives, and to use the same enclosure to store data on slower but higher capacity SATA drives.
Note, however, that it is not possible to use a SAS drive on a SATA controller.
For more information about SAS technology, refer to the HP technology brief titled
SCSI technology." 3

Small Form Factor (SFF) hard drives

SFF drives offer several advantages over 3.5-inch drives. The smaller physical size of the drives
increases the number of gigabytes per U that can be implemented in a server rack. SFF drives have
been shown to be more reliable than their larger counterparts, largely due to the use of smaller parts
and better vibration control.
Using SFF drives reduces power consumption and heat generation. SFF SAS drives consume
approximately half of the power used by a 3.5-inch drive of comparable capacity and therefore run
cooler than 3.5-inch drives.
Using SFF drives also improves performance. The smaller platter size results in reduced seek times
because the heads have a shorter distance to travel. RAID performance naturally benefits from having
more spindles.
Available at http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00302340/c00302340.pdf
3
Operational
support
x8
x8
x8
x4
x4
x4
x4
"Serial Attached
7