SATA DVD speed's too slow

[Joshua Isom]

I currently have an SATA DVD-RW drive for my computer.  I have to boot 
using a CURRENT kernel to get the drive recognized, and dmesg lists it 
as running at 3.3MB/s.  Running mplayer -dumpstream gets around 3 megs 
a second.  Copying off a data dvd gets about the same.  But I recall 
reading about playing a dvd before trying to get the data off of it 
when using dd, and it seems to work.  But the odd part is, it can get 
up to 20 megabytes a second.  Does anyone know how to get the higher 
speeds all the time?