"...Panasonic's goal was to combine two approved formats of the DVD forum in one drive. That is why the LF-D311 is called "DVD Burner". The drive supports writing at both DVD-R and DVD-RAM formats among with reading compatibility of all CD/DVD formats, except from DVD+RW. The writing with both DVD-R/RAM is done at 1X which means you will need almost one hour to write a full 4.7GB disc..."
FULL STORY @ CDRINFO (http://www.cdrinfo.com/hardware/panasonic-lfd311)