DVD buffer underrun

[Dennis R. Cohen]

On 2/29/04 at 5:28 PM, "Neil Poese" <npoese at earthlink.net> transmitted
the following electronic message:

>
>I've been trying to burn on an eMac superdrive and after a few
>successes, I've produced several coasters. I got a good DVD from
>iDVD3, then upgraded to iDVD4 and got another good one.
>
>Now I get buffer underrun alerts. I've tried going back to three, but
>that didn't help and I can't burn in either.
>
>Does anyone have any ideas?
>
>
>Thanks, Neil Poese
>

A "buffer underrun" indicates that your Mac isn't transferring data to
the burner quickly enough to keep up. The first thing I would suggest is
to eliminate/drastically minimize any other activity on the Mac while
the burn is in progress. Another thing would be to make sure that the
data to be burned is on a fast hard drive on a fast, unimpeded bus
(internal or FireWire, with no other devices on that particular bus).
You might also consider using "slower" media than the max, to slow down
the burn rate and provide a higher probability of avoiding the underrun.
Additionally, make sure that you have more than the minimum amount of
RAM available -- I would strongly recommend in excess of 512MB of RAM
for DVD burning.

Anecdotally, I ran into a couple of buffer underruns

Unfortunately, iDVD doesn't have a set of burning preferences like
Toast, where you can turn on "Buffer Underrun Protection" -- a method
where more RAM is used for more and larger data buffers. Additionally,
it doesn't let you set your burn speed to 1x, which would also reduce
the probability of buffer underrun (of course, you could use 1x media,
forcing the SuperDrive to burn at 1x as noted above).

-- 
Dennis R. Cohen
Mac Digital Photography
iLife Bible
and other titles