If you're using Windows, make sure DMA mode is enabled for the DVD-R
drive. It's usually set to PIO only by default. This will result in
HEAVY CPU usage and buffer under runs.

Don't forget, use an 80 conductor UDMA cable instead of a standard 40 conductor
IDE cable, especially if the drive is expected to run higher than UDMA33 (and
even then, you'd still want a UDMA cable). - Reinhart