A word of advise don't run out and buy a drive just because it DL, wait cause the reviews are all say compatibility problems. Infact this is from
cdrinfo's conclusion of the
BenQ DW830A:
"For sure, the increased 7.96GB will become handy to all those who wish to make 1:1 backups of DVD9 movies or even store two DVD movies at one disc (with the proper software). Users who wish just to store data, might find the DL solution not so good due to high incompatibility with DVD Writers ( & in general DVD readers for PC/MAC).
We don't know if the compatibility issues can be solved with firmware update or its just a media problem. We assume you wouldn't want to have a disc that can be read only by few drives, especially when includes 7.96GB of important data." Infact
cdfreaks gives a list and other than the drive and some liteon drives all drives failed to read the second layer.
It wouldn't be to nice to find out it can't be fixed with a firmware update. So buy the drive cause the price right not that its a DL.