Mid-Plane Options; Passive Mid-Plane; Active Mid-Plane With Intel Sas /Sas Raid Support; Figure 28. Passive Mid-Plane Board - Intel SR1500 - AXXMINIDIMM DDR-2 RAID Controller Cache Memory Manual

Peripheral and Hard Drive Sub-System
6.3

Mid-Plane Options

New to this generation of high density server system is the concept of the mid-plane. The mid-
plane is the interconnect between the server board and both the hot-swap backplane and
control panel. It is also used to determine which hard drive technology is to be supported. Two
different Mid-plane options are available for this platform 1) a cabled passive mid-plane capable
of supporting SATA ports from the server board or SAS/SATA ports from an add-in card; 2) an
active SAS / SAS RAID mid-plane. This section will describe the hard drive interface support of
each of the mid-plane boards.
6.3.1

Passive Mid-Plane

The passive mid-plane option is used when the system configuration requires the use of an
add-in SATA or SAS controller or the on-board SATA ports from the server board are used.
The drive control signals are cabled to the passive mid-plane.
The mid-plane plugs directly into the hot swap backplane using two edge connectors, routing
the hard drive signals to the appropriate hard drive connectors on the backplane. See Table 22.
Mid-Plane to Backplane Card Edge Connector #1 Pin-Out and
Table 23. Mid-Plane to Backplane Card Edge Connector #2 Pin-Out.
6.3.2 Active Mid-plane with Intel
The active mid-plane is used to provide SAS / SAS RAID support. It has integrated on to it an
Intel IOP80333 IO processor and an LSI* LSLSAS1068 3Gb/s SAS controller. Together they
provide support for up to eight SAS drives in this system. By default, this mid-plane option
provides software RAID levels 0, 1, and 10 utilizing Intel
the installation of optional RAID enablement devices, the mid-plane can support hardware RAID
levels 0, 1, 5, 10, and 50. The mid-plane attaches to the hot-swap backplane by two card edge
connectors which eliminates the need for any hard drive cables. The following sub-sections
describe the board level SAS / SAS RAID functionality.
42

Figure 28. Passive Mid-Plane Board

®
SAS /SAS RAID Support
Intel order number D31982-006
Intel® Server System SR1550AL
®
Embedded RAID Technology II. With
Revision – 1.3