[Debburn-devel] Issue when burning a DVD : DVD vs DMA speed

[Peter Samuelson]

[Olivier Médoc]
> >> Drive DMA Speed: 14497 kB/s 82x CD 10x DVD
> >> Current Secsize: 2048
> >...
> >>  DMA modes:  mdma0 mdma1 mdma2 
> >>  UDMA modes: udma0 udma1 *udma2 
> >>  AdvancedPM=no
> >>  Drive conforms to: Unspecified:  ATA/ATAPI-2 ATA/ATAPI-3 ATA/ATAPI-4 ATA/ATAPI-5

> Hum, I didn't know at first that my DMA was so slow. I searched quite
> a long time to find it.

OK, that looks a bit odd.  I think mode 2 is UltraDMA/33, with a
theoretical maximum bandwidth of 33 MB/s.  Which is twice what you're
apparently getting (15 MB/s).  Still, protocol overhead could account
for this, I suppose....

I wonder if the drive actually supports udma4 (UltraDMA/66) ... it is
possible that your ATA controller is limiting your UDMA modes because
it doesn't detect an 80-wire cable.  IDE cables come in two basic
types: a 40-wire cable looks like a (34-wire) floppy disk cable but a
bit wider; the 80-wire cable has the same connectors, but the cable
itself has twice as many wires, and they are a lot thinner.  This is
for better shielding between signal wires, and is required for any mode
faster than UDMA/33.  Indeed, it's recommended for UDMA/33 too.

So, yeah, check your cable to make sure you're using an 80-wire one.
Also, what type of ATA controller are you using for this?

Peter