Configuring power settings

When you install Windows Server operating system, you need to check for power settings, which are configured on such systems. There are several options for how you can verify which power setting plan is currently in use. If you open a command prompt or PowerShell, you can use the powercfg utility to see what plan is used on your server:

powercfg.exe -list

By default, you will see a Balanced plan selected, which is great for most servers and offers a lot of power-saving features, but usually this plan is not optimal for SQL Servers. SQL Server can put quite some load on the CPU and switching between CPU speeds may cost you precious time and performance. If you open the Task Manager tool, you can see that your CPU is not running on the maximum speed and may be running with a much lower value.

As an example, you can see the following screenshot from one of the physical servers with 2.4 GHz CPU, which is running on 1.25 GHz due to a power-saving plan:

You can verify this with tools like CPU-Z or similar, and the best option we have here is to update the power plan to high performance, which is common for SQL Server workloads. To update the power plan setting, you can either use a control panel where you can find settings for power options or use a command line again. When we listed the plans on the server with the previous command, you have seen in the output that they come with name and GUID. To update the plan via the command line, we need to use the GUID with the powercfg tool:

powercfg.exe -SETACTIVE <GUIDofThePlan>

The following screenshot gives an illustration of updating the plan via the command line:

Once the power plan is updated, the CPU is no longer using any power-saving mode and runs with full speed and possibly even turbo boot for extreme loads while performing complex queries on your server.