Home > Workload Solutions > Oracle > Best Practices > AMD-Based Oracle Best Practices on Dell PowerEdge R740 and PowerMax 2000 > CPU Best Practices > Day Three Best Practices > PowerEdge: NUMA Nodes per Socket
The BIOS setting NUMA Nodes per Socket enable the server administrator to specify value between 0 and 4. In this best practice, we increased the number of NUMA Nodes per Socket.
Category | Performance |
Product | PowerEdge R7525 |
Type of best practice | Performance Optimization |
Day and value | Day 3, Fine Tuning |
Overview
CPUs and local memory banks combine to create NUMA nodes. For example, in a two-socket server each of the two CPUs has a local memory bank, for a total of two NUMA nodes. When a CPU uses the local memory bank memory access is very fast. However, if a CPU must use a remote memory bank access times are not optimal. Thus, the goal is to fit the virtualized database into one NUMA node for the best possible performance.
AMD servers enable through BIOS to define more than one NUMA node per CPU. For example, changing NUMA Nodes per Socket from the default of 1 to 2 configures two NUMA nodes per local memory bank. This works by logically dividing the local memory bank into two equal parts. The resulting benefit is that each AMD CPU can use two NUMA nodes.
In this best practice, the NUMA Nodes per Socket was set to 2. The PowerEdge R7525 server had two sockets thus, we doubled the number of NUMA nodes from the original configuration of two to four. Additionally, the BIOS setting “L3 cache as NUMA Domain” was enabled to allow the large L3 cache to be used for NUMA nodes.
The goal of adding 2 NUMA nodes and using the L3 cache was to accelerate the eight virtualized databases.
Recommendation
Using the NUMA Nodes per Socket and L3 cache as NUMA Domain BIOS options provided a slight performance improvement for the following parameters:
These metrics remained the same, indicating no performance gains:
This best practice of increasing the NUMA Nodes per Socket might be most beneficial for consolidated database systems. With dedicated production servers that only service one database adding additional NUMA nodes most likely will not add value.
Implementation Steps
Use the following steps to view/update the NPS and L3 cache as NUMA parameters.
Additional Resources
Dell Support has BIOS settings for the AMD based servers like the PowerEdge R7525