cdrw & PIO4

Chuck Swiger cswiger at
Sat May 8 20:30:52 PDT 2004

anubis wrote:
> On Sun, 9 May 2004 3:17 am, w sx wrote:
[ ... ]
> Have a look at man ata.  Here is the important part
> ATAPI devices are set to PIO mode by default because severe DMA 
> problems are common even if the device capabilities indicate support.  
> You can always try to set DMA mode on an ATAPI device using 
> atacontrol(8), but be aware that your hardware might not support it 
> and can potentially hang the entire system causing data loss.

While this advice was reasonable some years ago-- and to the extent that 
broken ATA hardware still exists may still be relevant now-- but please note 
that the Original Poster is trying to use a CD/RW burner.  :-)

It doesn't matter too much if you happen to read a CD slowly, but one ought to 
use DMA rather than PIO when burning CDs or DVDs.


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