Specifications

126 IBM Power 770 and 780 Technical Overview and Introduction
To help you perform this study, a planning tool is included with AIX 6.1 Technology Level 4,
allowing you to sample actual workloads and estimate how expandable the partition's
memory is and how much CPU resource is needed. Any model Power System can run the
planning tool. Figure 3-4 shows an example of the output returned by this planning tool. The
tool outputs various real memory and CPU resource combinations to achieve the desired
effective memory. It also recommends one particular combination. In this example, the tool
recommends that you allocate 58% of a processor to benefit from 45% extra memory
capacity.
Figure 3-4 Output from Active Memory Expansion planning tool
Active Memory Expansion Modeled Statistics:
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Modeled Expanded Memory Size : 8.00 GB
Expansion True Memory Modeled Memory CPU Usage
Factor Modeled Size Gain Estimate
--------- -------------- ----------------- -----------
1.21 6.75 GB 1.25 GB [ 19%] 0.00
1.31 6.25 GB 1.75 GB [ 28%] 0.20
1.41 5.75 GB 2.25 GB [ 39%] 0.35
1.51 5.50 GB 2.50 GB[ 45%] 0.58
1.61 5.00 GB 3.00 GB [ 60%] 1.46
Active Memory Expansion Recommendation:
---------------------
The recommended AME configuration for this workload is to configure
the LPAR with a memory size of 5.50 GB and to configure a memory
expansion factor of 1.51. This will result in a memory expansion of
45% from the LPAR's current memory size. With this configuration,
the estimated CPU usage due to Active Memory Expansion is
approximately 0.58 physical processors, and the estimated overall
peak CPU resource required for the LPAR is 3.72 physical processors.