i'm super new to Ubuntu and by no means a computer expert. However, I did discover that disableing the VT-d in BIOS setting allowed my Asus u46e to boot ubuntu, even with eufi enabled. now everything works, including the fn keys to adjust screen brightness and volume, etc. Before I was booting with acpi=off and ubuntu only registered one processor, and over heated. now it registers four which is also wrong, but way better than before. I have dual core i7 processors.

hope this info will be a help to some of you with troubles.