Perhaps DMA is off... check with the following command
/sbin/hdparm /dev/hdc
Where "hdc" is the actual device name of your cdrom.
You should get something that looks like this:
Code:
/dev/hdc:
HDIO_GET_MULTCOUNT failed: Invalid argument
IO_support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 0 (off)
readonly = 0 (off)
readahead = 256 (on)
HDIO_GETGEO failed: Invalid argument
The "using_dma" line should probably be 1 (on). If it's not, log in as root, and run this command:
/sbin/hdparm -d1 /dev/hdc
See if that improves your performance.