I have a Lite-on LTC48161h.
It only reads DVD's at 8X, instead 16 x.
I'm running XP SP1, and I tested it using Nero's speed test.
I cant adjust it any faster.
The Lite-On LTC-48161H was connected as Secondary master and identified itself as LITE-ON COMBO LTC-48161H. Both autorun and DMA was enabled for both devices. (the other is TDK 880n).
I have the newest firmware kh0p.
XP says it's DMA 2.