IBM PureFlex System and IBM Flex System Products and Technology

205

Figure 5-38 shows the POWER7 processor die layout with major areas identified: Eight

POWER7 processor cores, L2 cache, L3 cache and chip power bus interconnect, SMP links,

GX++ interface, and integrated memory controller.

Figure 5-38 POWER7 processor architecture

5.4.8 Memory

Each POWER7 processor has an integrated memory controller. Industry standard DDR3

RDIMM technology is used to increase the reliability, speed, and density of the memory

subsystems.

Memory placement rules

The preferred memory minimum and maximum for the p260 and p24L are listed in Table 5-49.

Table 5-49 Preferred memory limits for p260 and p24L

Generally, use a minimum of 2 GB of RAM per core. The functional minimum memory

configuration for the system is 4 GB (2x2 GB). However, this configuration is not sufficient for

reasonable production use of the system.

LP and VLP form factors

One benefit of deploying IBM Flex System systems is the ability to use LP memory DIMMs.

This design allows for more choices to configure the system to match your needs.

C1

Core

L2

4 MB L3

L2

C1

Core

4 MB L3

Memory Controller

C1

Core

L2

4 MB L3

C1

Core

L2

4 MB L3

C1

Core

L2

4 MB L3

L2

C1

Core

4 MB L3

L2

C1

Core

4 MB L3

L2

C1

Core

4 MB L3

SMP

GX++ Bridge

Memory Buffers

Model Minimum memory Maximum memory

IBM Flex System p260 Compute Node 8 GB 256 GB (16x 16 GB DIMMs)

IBM Flex System p24L Compute Node 24 GB 256 GB (16 x 16 GB DIMMs)

206 IBM PureFlex System and IBM Flex System Products and Technology

Table 5-50 lists the available memory options for the p260 and p24L.

Table 5-50 Memory options for p260 and p24L

There are 16 buffered DIMM slots on the p260 and the p24L as shown in Figure 5-39.

Figure 5-39 Memory DIMM topology (IBM Flex System p260 Compute Node)

The memory-placement rules are as follows:

򐂰 Install DIMM fillers in unused DIMM slots to ensure effective cooling.

򐂰 Install DIMMs in pairs. Both need to be the same size.

򐂰 Both DIMMs in a pair must be the same size, speed, type, and technology. Otherwise, you

can mix compatible DIMMs from multiple manufacturers.

򐂰 Install only supported DIMMs, as described on the IBM ServerProven website:

http://www.ibm.com/servers/eserver/serverproven/compat/us/

Part

number

Feature

code

Description Speed Form

factor

78P1011 EM04 2x 2 GB DDR3 DIMM 1066 MHz

LP

78P0501 8196 2x 4 GB DDR3 DIMM 1066 MHz VLP

78P0502 8199 2x 8 GB DDR3 DIMM 1066 MHz VLP

78P0639 8145 2x 16 GB DDR3 DIMM 1066 MHz

LP

Requirement: Due to the design of the on-cover storage connections, clients who want to

use SAS HDDs

must use VLP DIMMs (4 GB or 8 GB). The cover cannot close properly if

VLP DIMMs and SAS HDDs are configured in the same system. This mixture physically

obstructs the cover.

Solid-state drives (SSDs) and LP DIMMs can be used together, however. For more

information, see 5.4.10, “Storage” on page 209.

SMI

SMI

SMI

SMI

SMI

SMI

SMI

SMI

POWER7

Processor 1

POWER7

Processor 0

DIMM 1 (P1-C1)

DIMM 2 (P1-C2)

DIMM 3 (P1-C3)

DIMM 4 (P1-C4)

DIMM 5 (P1-C5)

DIMM 6 (P1-C6)

DIMM 7 (P1-C7)

DIMM 8 (P1-C8)

DIMM 9 (P1-C9)

DIMM 10 (P1-C10)

DIMM 11 (P1-C11)

DIMM 12 (P1-C12)

DIMM 13 (P1-C13)

DIMM 14 (P1-C14)

DIMM 15 (P1-C15)

DIMM 16 (P1-C16)