It isn't a guessing game, Dave.

Suggest use a Power Supply Wattage Calculator, and be SURE,

http://support.asus.com/PowerSupply.aspx?SLanguage=en

http://extreme.outervision.com/psucalculatorlite.jsp

Need guidance in using either one, post back in a Comment.

Need all the specs. (Motherboard, {Biostar}, Processor, Ram Memory, graphics card (IF used), how many fans, how many optical drives, (CD/DVD drive), etc.

Regards,
joecoolvette