Re: [gentoo-user] new machine : DVD drive

[Pandu Poluan]

On Aug 20, 2012 8:51 PM, "Pandu Poluan" <pandu@××××××.info> wrote:
>
>
> On Aug 20, 2012 7:47 PM, "Andrea Conti" <alyf@××××.net> wrote:
> >
>
> [snip]
>
> > >
> > > Yes, +RW, -RW, but don't know much more on this other than older DVD
writers
> > > would only do one format not another and if you didn't pay attention
to the
> > > specification/limitations of your hardware you could end up buying
the wrong
> > > type of DVDs.  Someone more experienced on recording media could
answer this
> > > better.
> >
> > Every modern recorder does both standards; depending on both the burner
> > and the reader you might find that one standard works better than the
> > other (i.e. has lower read error rates). Trial and error seems to be the
> > only working approach...
> >
> > As for the standards, if you're just burning backups they're basically
> > equivalent. The +RW standard is theoretically more flexible as media can
> > be formatted in a "packet" mode which allows (almost) random r/w access,
> > but in my experience software support and reliability have always been
> > lousy, so forget about it.
> >
> > +RW media cannot be erased in the same way CD-RWs are erased, -- you can
> > only overwrite it with new data. -RW behaves the same as CD-RWs in this
> > regard.
> >
> > If you need rewritable DVD media with reliable random r/w access (but
> > this doesn't seem to be your case), there is a third standard (DVD-RAM)
> > which uses special disks with hardware sector marks. Drive support is
> > not hard to find nowadays (the drive you cited actually supports it),
> > but writing is slow, good media is expensive and the disks cannot be
> > read in most "normal" dvd drives; I have no idea about the state of
> > software support in Linux.
> >
>
> +RW *can* be erased, or else it won't be called RW :-)
>
> That said, the difference is much deeper than differing metadata. Among
which :
>
> * +RW uses Phase Modulation, -RW uses amplitude modulation. This gives
+RW much more robustness than -RW
>
> * +RW blanks provide more info on the energy level required to burn, IIRC
up to 4 energy levels each tuned to a certain burning speed (e.g., 1x, 2x,
4x, and 8x). This *greatly* improves the success probability of burning.
-RW only provides energy level info for the maximum burning speed; if your
drive doesn't support that speed, it'll have to guess, and the results are
usually ungood
>
> More history :
>
> The CD Standard was originally developed by Philips, then adapted to the
data world requirements, including CD-R(W).  The DVD-R standard was
originally developed by Panasonic, but Philips had a spat with Panasonic
because in Phillips' view, the CD-R standard has shortcomings they
(Philips) want to fix; Panasonic was more interested in getting DVD-R out
of the door asap. This resulted in Philips -- together with someone else,
was it Sony? -- to independently released the DVD+R standard.
>
> CMIIW
>

Aha, found the page comparing +R(W) and -R(W) :

http://www.myce.com/article/why-dvdrw-is-superior-to-dvd-rw-203/

tldr: DVD+R(W) is technically a better standard. Use it.

Rgds,