Chapter 2. Architecture and technical overview
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integrated SAS controllers each physically provide 3.1 GB write cache. Working as a pair,
they provide mirrored write-cache data and controller redundancy. The cache contents are
designed to be protected by built-in flash memory in case of power failure. If the pairing is
broken, write cache is not used after existing cache content is written out to the drive, and
performance will probably be slowed until the controller pairing is re-established.
Figure 2-25 shows the EXP30 drawer.
Figure 2-25 The EXP30 SSD drawer
Each controller is connected to a GX++ 2-Port PCIe adapter (FC 1914 CCIN 2B94) in a
server over a PCIe x8 cable. Usually both controllers are attached to one server, but each
controller can be assigned to a separate server or a logical partition.
Table 2-27 lists the RAID levels for the AIX, IBM i, Linux operating system that are supported
by the controller.
Table 2-27 Supported RAID levels
The EXP30 Ultra SSD I/O drawer (FC EDR1) delivers up to 480,000 IOPS (read only), up to
410,000 IOPS (60% read and 40% write), or up to 325,000 IOPS (100% write), and has up to
30% performance improvement over the previous version of the EXP30 (FC 5888).
A maximum number of two EXP drawers can be attached to the Power 750 and Power 760
server, depending on the operating system. Table 2-28 list the quantity of EXP30 drawers
which can be attached to the Power 750 and Power 760 running different operating systems.
Table 2-28 Quantity of EXP30 attachments
RAID level
Operating system
RAID 0
AIX, Linux
RAID 1
a
a. Provided by operating system Logical Volume Manager (LVM)
AIX, IBM i, Linux
RAID 5
AIX, IBM i, Linux
RAID 6
AIX, IBM i, Linux
RAID 10
AIX, Linux
System
AIX
IBM i
Linux
Power 750
One or two
One
One or two
Power 760
One or two
One
a
One or two
