Re: DVD Compatiblity issue
> ... tried using -speed=4 and it still took 28 minutes. Here the
> reported speed was 4.1x though. This recording time would seem to
> me to be closer to 2x speed. The "write" LED is illuminated
> constantly so I do not think there are any buffer under-runs that
> would account for the slower performance. However, in regard to
> the original problem, since the -speed=4 apparently did not really
> work but the media appears to be fully readable by all my drives.
Meaning that you can't reproduce the problem... Well, varying results
might be indication of poor media support in firmware. I would still
recommend to try -speed=1 option and maybe even stick to it for *this*
media brand/batch, just to be on the safe side.
> In regard to using different media, it would appear from the
> media-info reports that DVD-R does not identify the manufacturer.
> So how can I identify who made it? Since identification appears to
> be impossible on DVD-R media this seems to be most impractical.
Don't jump into conclusions:-) You can't really say "DVD-R does not
identify the manufacturer" based on experience with one unit, can you? I
mean it most likely your unit which doesn't/fails to pull that
information from media, not like it's fundamentally impossible to
identify manufacturer of the DVD-R media. I don't know if following
holds true even for any DVD-dash capable unit, but some DVD+units don't
disclose manufacturer ID for blank media, in other words you have to
record it to be able to pull that information.
> I had a spindle of 4x DVD+R media here as well.
Generally speaking 4x rating appearing on the case does not
automatically mean that it will be recorded at that particular speed in
every 4x-capable unit. Ultimately it's up to unit firmware to pick the
> I wrote one without
> using the -speed option at all. For the same 4125 Mb file system
> it took 23 minutes. About the same as the 2.4x +RW media.
Then some units tend to remember velocity settings, see
http://fy.chalmers.se/~appro/linux/DVD+RW/hcn.html for further
information. This and above means that it's several variables problem
and we don't know which really applies in this particular case. Yes,
it's jungle out there...
> It reported 4.1x recording speed.
You mean growisofs printed 4.1x in the very beginning, right? A.