Quoted from - doc.sitecore.net/.../configure_sitecore_device_detection
(Optional) Disable Device Detection
The Device Detection module is enabled by default. However, if you want to prevent the Device Detection client from contacting the Device Detection service every 10 minutes (which is the default setting), then you can disable the module. There are two ways to disable it,
In the sitecore/Settings folder, set DeviceDetection.Enabled to false. <setting name="DeviceDetection.Enabled" value="false" /> The default setting is "true".
Add the .disabled extension to the Sitecore.CES.DeviceDetection.config file in the (App_Config/Include/CES/) folder, for example, Sitecore.CES.DeviceDetection.config.disabled