Burned vs pressed CDs

[Lennart Sorensen]

On Sun, Dec 05, 2004 at 10:27:08AM -0500, Fraser Campbell wrote:
> On Sunday 05 December 2004 09:18, David J Patrick wrote:
> 
> > In attempts to install ubuntu, on my thinkpad, I failed several times
> > using a freshly burned CD, even though the md5 sums were good. Then,
> > using an official ubuntu CD, it worked like a charm. I have also read
> > about other folks whose CDrom drives would only worked with "pressed"
> > CDs, not "burned" CDs. What's the difference ?
> 
> Recently I was doing a lot of Debian installs with modified versions of the 
> installer CD.  Instead of thowing out dozens of discs I wanted to use 
> rewriteables.  I had Maxell 1x-4x CDRWs.
> 
> The Maxells burned just fine, the md5sums checked out, and the disks even 
> booted and worked properly on most systems that I tried.  However when it 
> came to an IBM xseries server (brand new) it would not boot.  By accident I 
> discovered that the CDs might actually be able to boot ... after a little 
> more than 30 minutes the Debian Installer splash screen appeared, and 
> pressing enter the kernel did start to load but the progress was painfully 
> slow (4 dots after 20 minutes).  Some of the Maxells had never been burned, 
> some of those that I tried were reburns.  I tried reducing the burn rate to 
> 1x but that made no difference.
> 
> I went out and purchased some alternate 4x-10x CDRW media (5 verbatim, 1 
> fujifilm) and the IBM booted those absolutely fine ... verbatim burned at 10x 
> and I believe fujifilm had burned at 4x.
> 
> So I don't know what the difference really is but I'd be willing to bet that 
> there is media out there that will work for you.

There are different types of CD-RW media.  There is the original CD-RW
format (1x to 4x), then there is highspeed CD-RW (4x - 10x) and then
there is ultraspeed CD-RW (10x+), and a writer needs the right type of
media to write.  You can't write a 10x high speed cd-rw in a 4x cd-rw
burner at all.  Hence the reason the logo on the media is different.
Some drives can not read any cd-rw, some can read certain types, but not
necesarily very well.  But the different types of CD-RW are indeed very
different physically.

Lennart Sorensen
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