Burning 2 DVD simultaneously... slow

[ted leslie]

make sure your dvd burners are operating dma mode.
if the dvd you are creating is 10,000 of files having to be accessed and
formatted into ISO fs format, hmmm may be enough work (doing two at a time)
to reasonable (and no surprise) bottle neck something.
but if you are reading straight iso files then sounds like not-dma to me.
could also be dvd drives are working with a burn-proof (or variant) that
is having issues. Download a free copy of Nero for linux (30 day eval)
see how it does .. not sure about dual burning with it, or have it burn one,
while using grow for the other, try k3b and brasero as well,
maybe with one you will find some clues.

tl

On Mon, Feb 21, 2011 at 8:03 PM, William Park <opengeometry-FFYn/CNdgSA at public.gmane.org> wrote:
> My CPU is 3.2GHz dual-core, and I was burning Debian-6.0 DVD 1-8
> actually.  My HD is ubiquitous 500GB SATA, so it should be fast enough.
> The command I use is
>
>    growisofs -dvd-compat -Z /dev/dvd=debian-6.0.0-amd64-DVD-1.iso
>
> Maybe it's the program, because it's designed for generating ISO
> structure on the fly.  But, I'm reading straight ISO files without doing
> anything.
> --
> William
>
> On Mon, Feb 21, 2011 at 03:20:50PM -0500, ted leslie wrote:
>> I have set up a box to do 4 at a time, and experienced similar.
>> the issue was, that in the burning, the process is assembling the iso
>> (on the HD or in memory as it goes) and this takes CPU, at the time
>> i just had single core.
>> if you have the ISO's all on hd, then to do 2 dvd burns you are just
>> reading from the HD (2 iso's concurrently) and writing to your two dvd burners,
>> but if you don't burn from pre-assembled iso files,
>> you are asking the burn process (both of them) so read
>> the files from HD and assemble them on fly,
>> then out to the DVD. If you have lots of small files as well
>> you are looking at a lot of head movement on the HD,
>> and also DVD burners can be quite fast, not as fast as a
>> HD , but still pretty quick. To rule out iso assembly issues,
>> you should attempt the dual burn from just ISO files,
>> and if your HD is say 2x faster then the combined throughtput burn
>> of your dvd burners, then you would expect the dual burn to take about
>> as fast as a single.
>>
>> tl
>>
>> On Mon, Feb 21, 2011 at 12:42 PM, William Park <opengeometry-FFYn/CNdgSA at public.gmane.org> wrote:
>> > I usually burn 1 DVD at a time, so I didn't noticed this before.  When
>> > burning 2 DVD-RW simultaneously (one SATA burner and one USB burner),
>> > the speed crawls and fluctuates.  I would've thought modern computer is
>> > more than capable of handling 2 DVDs at the same time.  Anyone
>> > experienced this?
>> > --
>> > William
> --
> The Toronto Linux Users Group.      Meetings: http://gtalug.org/
> TLUG requests: Linux topics, No HTML, wrap text below 80 columns
> How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists
>
--
The Toronto Linux Users Group.      Meetings: http://gtalug.org/
TLUG requests: Linux topics, No HTML, wrap text below 80 columns
How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists