IBM Power 780 Technical Overview And Introduction page 162

Identical pages within the same or different LPARs each require their own unique physical
memory page, consuming space with repeated information.
Logical Memory
KEY:
Figure 3-13 Active Memory Sharing shared memory pool without Active Memory Deduplication
enabled
Active Memory Deduplication allows the hypervisor to dynamically map identical partition
memory pages to a single physical memory page within a shared memory pool. This way
enables a better utilization of the Active Memory Sharing shared memory pool, increasing the
system's overall performance by avoiding paging. Deduplication can cause the hardware to
incur fewer cache misses, which also leads to improved performance.
148
IBM Power 770 and 780 (9117-MMD, 9179-MHD) Technical Overview and Introduction
LPAR1
Logical Memory
U U
U U U U U
U U
D D D
Mappings
D D D D U
U U U U U
AMS shared memory pool
D Duplicate pages
U
Unique pages
LPAR2 LPAR3
Logical Memory
U
U U U U
U U U
D
Without
Active Memory
Deduplication
U U U U U
U U U U U
U
U
U
U
U