DMA

[Alexander Jacob Tsykin]

On Wednesday 24 May 2006 08:26, Jeff Waugh wrote:
> <quote who="Sean Hammond">
>
> > >If DMA is disabled by default, then you're running the risk of crashing
> > >or damaging your machine by enabling it.
> >
> > So I've heard. Does this mean that Windows enables DMA by default on many
> > such systems and runs the risk, whereas Ubuntu/Debian/(Linux?) are more
> > cautious?
>
> Here are two reasons why DMA might be disabled:
>
>  1) The hardware does not function correctly, or causes errors when DMA is
>  enabled
>
>  2) The drivers do not function correctly, or cause errors when DMA is
>  enabled
>
> In the case of (2), then yes, Windows may enable DMA by default on the same
> device. But it would not be a good idea for us to enable it, or let a user
> think that he/she should enable it. After all, how many users know what DMA
> really means, beyond "DMA go faster!"?
>
> Scott isn't talking about fixing problems like lack of X configuration
> tools though - he's talking about the appropriateness and dangers of
> exposing the underlying machinery of the computer to users who don't
> understand it... and don't care to understand it.
>
> DMA really is a more/less magic setting. Why burden the user with that
> choice?

Because only rarely it seems, and certainly not in my case, the system makes 
the correct choice