yes you can. infact ibm used to sell 3 options depending on graphic solution and docking station. this is also a major problem in some intel based notebook that had too low of a watt. it would make the 5 series chipsets go to idle even under a load. result was horible perforance under media play. games too. there a disable idle tweek just for that reason that a reg patch that allows windows power setting to open a new setting under power options under cpu settings. this tweek works for all intel based chips so you can disable it under pluged in mode. a 65watt is min i would ever use a 90 if i had a powerfull cpu and graphic option or else you risk it not ever opening up if your need full power.