I have tested mine and downclocked my i7 CPU to 1.8ghz using windows power options and ran heaven bench whilst XTU is open. It starts off at 25w TDP as normal but eventually, it will drop back to 15w without a fan. (takes a little longer) Something else I have found out recently, If you use a fan to keep the TDP at 25w then the battery will drain because the adapter doesn't give out enough power. On mine it drains at about 20% per hour whilst plugged in and gaming. If you let the TDP drop to 15w then the battery wont drain.