Avago Technologies MegaRAID SAS 8204ELP - Manual (Page 26)

1-12 Overview
Copyright © 2007 by LSI Corporation. All rights reserved.
supports up to 240 physical disks, but the maximum number of arrays is
limited to 128.
In addition, though you can have up to eight virtual disks per array, and
up to 16 arrays per controller for the SAS 8704ELP, there is a limit of 64
virtual disks per controller. Because of this constraint, the 16 arrays
cannot all contain eight virtual disks at the same time.
Note: The maximum number of hot spares per controller is equal
to the maximum number of drives per controller.
These RAID controllers support 64-bit logical block addressing (LBA),
which makes it possible to connect a large number of drives to the RAID
controller, directly and through expanders. However, the actual number
of drives that you can attach depends on the limits listed in
Table 1.1
rather than by actual RAID volume capacity.
1.6.3 SATA II Features
The following list describes the SATA II features of the RAID controllers:
•
Supports SATA II data transfers of 3.0 Gbits/s
•
Supports STP data transfers of 3.0 Gbits/s
•
Provides a serial, point-to-point storage interface
•
Simplifies cabling between devices
•
Eliminates the master-slave construction used in parallel ATA
•
Allows addressing of multiple SATA II targets through an expander
•
Allows multiple initiators to address a single target (in a fail-over
configuration) through an expander
1.6.4 PCI Express Performance
The following list describes the PCI Express performance features of the
RAID controllers:
•
Provides a PCI Express interface that:
– Supports a dedicated PCI Express bus
– Supports x4, x8, or x16 lane configuration
– Supports transfer rates of up to 2.5 Gbits/s per lane