Samsung note three is doing better working if its android version becomes updated for updation version you need 1.7 mb of free space and u will be told to clear more space if required .
It will take 8 minutes to prepare your devices for the update and another 14 minutes to install android 5.0 on your phablet .Before this operation make sure your battery is charged atleast 50 % once android version will be updated than your galaxy note 3 do work better.