I did call Asus and they gave me an email address to write for an answer..... No reply so far ..... I work at TigerDirect.com and a customer was asking our staff and techs as he , for some reason, needs to know as a very picky and tech oriented person...... Who knows , but it got us all wondering and no one could answer the question...... I will post the answer Asus gives me if I ever get a reply......Just thought those in the know , might know........ Let me know if you may have insight into this..........