IBM Power 780 User Manual

Chapter 3. Virtualization 127
Table 3-2 lists the differences between these modes.
Table 3-2 Differences between POWER6 and POWER7 compatibility mode
3.3 Active Memory Expansion
Active Memory Expansion enablement is an optional feature of POWER7+ processor-based
servers that must be specified when creating the configuration in the e-Config tool, as follows:
IBM Power 770 (FC 4791)
IBM Power 780 (FC 4791)
This feature enables memory expansion on the system. Using compression/decompression
of memory content can effectively expand the maximum memory capacity, providing
additional server workload capacity and performance.
Active Memory Expansion is a POWER technology that allows the effective maximum
memory capacity to be much larger than the true physical memory maximum.
Compression/decompression of memory content can allow memory expansion up to 100%,
which in turn enables a partition to perform significantly more work or support more users
with the same physical amount of memory. Similarly, it can allow a server to run more
partitions and do more work for the same physical amount of memory.
Active Memory Expansion is available for partitions running AIX 6.1, Technology Level 4 with
SP2, or later. Linux will support Active Memory Expansion on the next major versions.
Active Memory Expansion uses CPU resource of a partition to compress/decompress the
memory contents of this same partition.The trade-off of memory capacity for processor cycles
can be an excellent choice, but the degree of expansion varies based on how compressible
POWER6 and POWER6+
mode
POWER7
mode
Customer
value
2-thread SMT 4-thread SMT Throughput performance,
processor core utilization
Vector Multimedia Extension/
AltiVec (VMX)
Vector scalar extension (VSX) High-performance computing
Affinity OFF by default 3-tier memory, Micropartition
Affinity, Dynamic Platform
Optimizer
Improved system performance
for system images spanning
sockets and nodes
򐂰 Barrier Synchronization
򐂰 Fixed 128-byte array,
Kernel Extension Access
򐂰 Enhanced Barrier
Synchronization
򐂰 Variable Sized Array, User
Shared Memory Access
High-performance computing
parallel programming
synchronization facility
64-core and 128-thread scaling 򐂰 32-core and 128-thread
scaling
򐂰 64-core and 256-thread
scaling
򐂰 128-core and 512-thread
scaling
򐂰 256-core and 1024-thread
scaling
Performance and scalability for
large scale-up single system
image workloads (such as
OLTP, ERP scale-up, and
WPAR consolidation)
EnergyScale CPU Idle EnergyScale CPU Idle and
Folding with NAP and SLEEP
Improved energy efficiency

IBM Power 780 Specifications

General

Brand	IBM
Model	Power 780
Category	Server
Language	English