DMA disabled on device _NEC - DVD+-RW ND-6650A
With most modern CD/DVD devices enabling DMA highly increases read/write performance. If you experience very low writing speeds this is probably the cause.
Solution: Enable DMA temporarily as root with 'hdparm -d 1 /dev/hdc'.



root@higher /home/joshua $ hdparm -d 1 /dev/hdc

/dev/hdc:
 setting using_dma to 1 (on)
 HDIO_SET_DMA failed: Operation not permitted
 using_dma     =  0 (off)
root@higher /home/joshua $