Mar 12, 2022
Memory features – Introduction to Power E1080
1.5.3 Memory features
This section describes the memory features that available on a Power E1080 server. Careful selection of these features helps the user to configure their system with the correct amount of memory that can meet the demands of memory intensive workloads. On a Power E1080 server, the memory features can be classified into the following feature categories:
Ê Physical memory Ê Memory activation
These features are described next.
Physical memory features
Physical memory features that are supported on Power E1080 are the next generation differential dual inline memory modules, called DDIMM (see 2.3, “Memory subsystem” on page 72). DDIMMS that are used in the E1080 are Enterprise Class 4U DDIMMs.
The memory DDIMM features are available in 32-, 64-, 128-, and 256-GB capacity. Among these DDIMM features, 32 GB and 64 GB DDIMMs run at 3200 MHz frequency and 128 GB and 256 GB DDIMMs run at 2933 MHz frequency.
Each system node provides 64 DDIMM slots that support a maximum of 16 TB memory and a four system node E1080 can support a maximum of 64 TB memory. DDIMMs are ordered by using memory feature codes, which include a bundle of four DDIMMs with the same capacity.
Consider the following points regarding improved performance:
Ê Plugging DDIMMs of same density provides the highest performance. Ê Filling all the memory slots provides maximum memory performance.
Ê System performance improves when more quads of memory DDIMMs match.
Ê System performance also improves as the amount of memory is spread across more DDIMM slots.
For example, if 1TB of memory is required, 64 x 32 GB DDIMMs can provide better performance than 32 x 64 GB DDIMMs
Chapter 1. Introduction to Power E1080 19
Figure 1-6 shows a DDIMM memory feature.
Figure 1-6 New DDIMM feature
Table 1-10 lists the available memory DDIMM feature codes for the Power E1080.
Table 1-10 E1080 memory feature codes
Memory activation features
Software keys are required to activate part or all of the physical memory that is installed in the Power E1080 to be assigned to logical partitions (LPAR). Any software key is available when memory activation feature is ordered and can be ordered at any time during the life-cycle of the server to help the user scale up memory capacity without outages, unless an more physical memory upgrade and activation are required.
A server administrator or user cannot control which physical memory DDIMM features are activated when memory activations are used.
The amount of memory to activate depends on the feature code ordered; for example, if an order contains two of feature code EDAB (100 GB DDR4 Mobile Memory Activation for HEX), these feature codes activate 200 GB of the installed physical memory.
20 IBM Power E1080: Technical Overview and Introduction
Different types of memory activation features that are available for the Power E1080 server are known to the PowerVM hypervisor as total quantity for each type. The PowerVM hypervisor determines the physical DDIMM memory to be activated and assigned to the LPARs.
Similar to processor core activation features, different types of permanent memory activation features are offered on the Power E1080 server. For more information about the available types of activations, 1.5.2, “Processor features” on page 16.
Orders for memory activation features must consider the following rules:
Ê The system must have a minimum of 50% activated physical memory. It can be activated by using static or static and mobile memory activation features.
Ê The system must have a minimum of 25% of physical memory activated by using static memory activation features.
Ê When a Power E1080 is part of a PEP 2.0 environment, the server must have a minimum of 256 GB of base memory activations.
Consider the following examples:
Ê For a system with 4 TB of physical memory, at least 2 TB (50% of 4 TB) must be activated.
Ê When a Power E1080 is part of a PEP 1.0 environment, a server with 4 TB of physical memory and 3.5 TB of activated memory requires a minimum of 896 GB (25% of 3.5 TB) of physical memory activated by using static activation features.
Ê When a Power E1080 is part of a PEP 2.0 environment, a server with 4 TB of physical memory requires a minimum of 256 GB of memory activated with base activation features.
Table 1-11 lists the available memory activation feature codes for Power E1080. The Order type column provides indicates whether the feature code is available for an initial order only, or also with a MES upgrade on a existing server only, or both.
Table 1-11 Memory activation features.
Chapter 1. Introduction to Power E1080 21
