IBM NeXtScale System Planning And Implementation Manual page 126

The ServeRAID M5120 SAS/SATA Controller has the following specifications:
Eight external 6 Gbps SAS/SATA ports
Up to 6 Gbps throughput per port
Two external x4 mini-SAS connectors (SFF-8088)
Supports RAID 0, 1, and 10
Supports RAID 5 and 50 with optional M5100 Series RAID 5 upgrades
Supports RAID 6 and 60 with the optional M5100 Series RAID 6 upgrade
Supports 512 MB battery-backed cache or 512 MB or 1 GB flash-backed
cache (cache)
PCIe 3.0 x8 host interface
Based on the LSI SAS2208 6 Gbps ROC controller
Supports connectivity to the EXP2512 and EXP2524 storage expansion
enclosures
For more information, see the IBM Redbooks Product Guide ServeRAID M5120
SAS/SATA Controller for IBM System x, TIPS0858:
http://www.redbooks.ibm.com/abstracts/tips0858.html?Open
The ServeRAID M5120 SAS/SATA Controller supports connectivity to the IBM
System Storage external expansion enclosures that are listed in Table 4-32. Up
to nine expansion enclosures can be daisy-chained per one M5120 external port.
For better performance, distribute expansion enclosures evenly across both
M5120 ports.
Table 4-32 IBM System Storage external expansion enclosures
Part
number
174712X
174724X
The external SAS cables that are listed in Table 4-33 on page 109 support
connectivity between external expansion enclosures and the ServeRAID M5120
SAS/SATA Controller.
108
IBM NeXtScale System Planning and Implementation Guide
Description
IBM System Storage EXP2512 Express
IBM System Storage EXP2524 Express
Maximum supported
per one M5120
18
9