Drive read/write slow

[Dave Gutteridge]

Fedora List,

    Hello, I'm new to the list, and to Fedora. Although I'm somewhat of 
a newbie to Linux, it's my goal to make Fedora my primary OS, and to 
eventually remove Windows XP from my system. I have a somewhat old 
Pentium 3 CPU, with two internal DVD drives, one internal CD-ROM drive, 
and one external (USB) DVD burner drive. I have one 30GB HD, which I 
have partitioned into 10GB for Windows, and 20 GB for Fedora.
    I'm running Fedora Core 4.

    I have a problem with pretty much all of the DVD/CD drives. Copying 
data off them is exceptionally slow, and invariably leads to some kind 
of buffer under run (?) which causes the copy process to fail.
    I posted on some Linux related forums, and someone suggested that I 
check if DMA is enabled, and suggested some commands. When I reported 
the results back, it seemed that I did have DMA enabled, so I'm not 
entirely sure what else could be the cause of the slow drives.

    There are other issues. The CD drive behaves erratically. Sometimes 
it is unresponsive to "eject" commands. The main internal DVD sometimes 
hangs when inserting a new disk. If a DVD disk is in the drive when I am 
booting the system, it will sometimes cause the boot process to stall 
indefinitely. The external DVD-burner is the most reliable of all of 
them, but even still, it will fail in copying files unless the number of 
files to be copied, or the total size in bytes of all files is very small.

    I have not tried burning any DVDs or CDs yet as it seems extremely 
unlikely I'll be successful there if I can't read from discs. I don't 
want to go tearing through blank DVDs in experimentation.

    To verify that the drives themselves are working okay, I rebooted 
into Windows and I can read data off of them without problem and with 
reasonably good speed. So it would seem the issue is in how Fedora is 
accessing them.

    Can anyone here suggest how I might resolve what the problem is in 
reading from the DVD/CD drives and what might get them operating 
properly? Please keep advice on a level understandable to someone who is 
relatively new to Fedora and Linux.

    If this is the wrong list for this kind of general inquiry, please 
direct me to a better list.

    Thank you for taking the time to read this.

Dave