Razer Fan Hub 3900rpm limit ?

I am using a razer fan hub and have been with my Razer fans , I recently took my water pump off my mobo connector to use with the hub , I wanted to delete armory create and the pump was the only think it still controlled . What i noticed is that the razer hub is limiting my Ekwb combo pump to 3999 rpm at 100 percent , though max speed is 4500 , Is there a way to fix this or should i just plug it back into the motherboard pump header ... Thanks.. Marcus