Oracle X4 series, Administration Manual

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Understanding Elastic Computing
Understanding Elastic Computing
Elastic computing refers to the ability to maximize performance by selectively activating and
deactivating processor cores, which causes a subsequent increase or decrease in maximum
frequency of the remaining active cores. This allows you to set the optimal balance between
core count and maximum frequency for a given workload.
Each core supports one or two virtual processors, depending on whether hyperthreading is
enabled or not. Virtual processors support threads ; increasing the number of active cores
increases the number of virtual processors, which allows the application to support more
threads.
Deactivating all of the virtual processors associated with a core deactivates the core.
Note -
For Linux operating systems, virtual processors are called logical processors .
Some workloads are not able to take advantage of having many threads, but instead benefit
from having fewer threads running at higher frequencies.
Before elastic computing, you had to order your server with a processor designed to have the
optimal core count and frequency for your specific workload. Elastic computing gives you the
ability to configure a single server dynamically to meet the needs of many types of workloads.
You can activate or deactivate cores using the Solaris or Oracle Linux OS, or the BIOS Setup
Utility.
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Using the OS commands, you can activate and deactivate virtual processors while the
application is running, causing the corresponding cores to become inactive. This is the
preferred method; however it requires that you have the Oracle Linux or Oracle Solaris
operating systems. Using this method you can adjust performance dynamically, as often as
necessary.
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If you have any other supported operating system, you can activate or deactivate cores using
the BIOS Setup Utility. While you can change the settings whenever you wish, this method
requires rebooting the server.
Note -
If hyperthreading is enabled, to deactivate a core, you must deactivate both virtual
processors associated with that core.
Cores and Maximum Frequency
The following table shows the relationship between active cores and maximum frequency.
208 Oracle X4 Series Servers Administration Guide • April 2016