Group Policy refresh interval for domain controllers
Computer Configuration\Administrative Templates\System\Group Policy
Specifies how often Group Policy is updated on domain controllers while they are running (in the background). The updates specified by this policy occur in addition to updates performed when the system starts.
By default, Group Policy on the domain controllers is updated every five minutes.
You can specify an update rate from 0 to 64,800 minutes (45 days). If you select 0 minutes, the domain controller tries to update Group Policy every 7 seconds. However, because updates might interfere with users' work and increase network traffic, very short update intervals are not appropriate for most installations.
This policy also lets you specify how much the actual update interval varies. To prevent domain controllers with the same update interval from requesting updates simultaneously, the system varies the update interval for each controller by a random number of minutes. The number you type in the random time box sets the upper limit for the range of variance. For example, if you type 30 minutes, the system selects a variance of 0 to 30 minutes. Typing a large number establishes a broad range and makes it less likely that update requests overlap. However, updates might be delayed significantly.
If you disable this policy, the domain controller updates Group Policy every 5 minutes (the default). To specify that Group Policy for domain controllers should never be updated while the computer is in use, enable the Disable background refresh of Group Policy policy.
This policy is used only when you are establishing policy for a domain, site, organizational unit (OU), or customized group. If you are establishing policy for a local computer only, the system ignores this policy.