SEPM - how often does it sync with AD

Hello,

I currently have majority of the containers setup without AD sync, however, i have a couple that are synced with AD.  Does anyone know how often this syncs? Under Admin/servers/servername/right click properties/directory servers, doesnt have the syncrhonize with directory servers checked so i am not sure where else i can see this setting.  

FWIW, if i select the AD container and click sync now, it works right away.

Thanks