nxe2god or iso2god is the way to go! doesn't require an insane cpu/ram, it's mostly a hdd task, so keep it from one internal hdd to another internal or from one to the same. don't mess about with usb drives and such.
btw ISO2GOD also has the neatest function, FTP! once one game has finished converted, it will automaticlly ftp the folder to the 360 in the correct folder, while it continiues to convert the next game in the list. :cool2: