Memory Subsystem; Registered Dimm; Memory Placement Rules - IBM Power 720 Overview

2.3 Memory subsystem

The Power 720 is a one-socket system that supports a single POWER7+ processor module.
The server supports a maximum of 16 DDR3 DIMM slots, with eight DIMM slots included in
the base configuration and eight DIMM slots available with an optional memory riser card.
Memory features (two memory DIMMs per feature) supported are 8 GB, 16 GB, 32 GB, and
64 GB running at speeds of 1066 MHz. A system with the installed optional memory riser
card has a maximum memory of 512 GB.
The Power 740 is a two-socket system supporting up to two POWER7+ processor modules.
The server supports a maximum of 32 DDR3 DIMM slots, with eight DIMM slots included in
the base configuration and 24 DIMM slots available with three optional memory riser cards.
Memory features (two memory DIMMs per feature) supported are 8 GB, 16 GB, 32 GB, and
64 GB run at speeds of 1066 MHz. A system with three installed optional memory riser cards
has a maximum memory of 1024 GB.

2.3.1 Registered DIMM

Industry standard DDR3 Registered DIMM (RDIMM) technology is used to increase reliability,
speed, and density of memory subsystems by putting a register between the DIMM modules
and the memory controller. This register is also referred to as a buffer.

2.3.2 Memory placement rules

The following memory options can be ordered:
8 GB (2 x 4 GB) Memory DIMMs, 1066 MHz (FC EM08)
16 GB (2 x 8 GB) Memory DIMMs, 1066 MHz (FC EM4B, CCIN 31FA)
32 GB (2 x 16 GB) Memory DIMMs, 1066 MHz (FC EM4C)
64 GB (2 x 32 GB) Memory DIMMs, 1066 MHz (FC EM4D)
A minimum of 8 GB memory is required for a Power 720 system or a Power 740 system using
one processor card. Table 2-5 lists the maximum memory that is supported on the Power 720.
Table 2-5 Power 720 maximum memory
Processor cores
4-core
6-core
8-core
Note: A Power 720 system with the 4-core processor module (FC EPCK) does not support the 32 GB
(FC EM4C) and 64 GB (FC EM4D) memory features.
One memory riser card
64 GB
256 GB
Chapter 2. Architecture and technical overview
Two memory riser cards
64 GB
512 GB
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