My GeForce2 card finally crapped out after running nicely for the last couple of years so I went looking for a new and inexpensive card. I picked up a PCI version of the GeForce4 MX 4000 w/64MB. I also picked up a new hard drive (120GB WD) and a DVD burner to shovel into my machine with an Athlon 1600 on a Soyo Dragon w/512MB. I already had two hard drives and 2 CD-ROM drives in the machine so I plugged the new drive into one of the unused Promise IDE RAID ports. I brought my Fedora systep up and partitioned the new drive and moved some data to it with no problems.
The video card seemed to work with the old nVidia drivers I had installed (I had to use old drivers on the GeForce2 to avoid lockup problems). I soon was able to lock up X with the new card on command. Like many other people's experiences X would lock but the mouse would still work and I could log in via SSH from another machine and kill X and restart it. First thing I did was try the latest drivers with the same result. To get X to lock all I do is start xcdroast and master an image file of about 500-600MB. It locks about half way through. I tried all the suggested tricks I could find in the forums (NvAGP set to 0, noapic, etc, etc). I did figure out how to stop the lockups. If I turn off DMA on the new hard drive (hdparm -d 0 /dev/hdf) I no longer receive lockups. Problem with this is the hard drive becomes painfully slow (comparatively). Now, moving data around on the new drive outside of X works just fine. There is never any sort of error anywhere (including in all of the logs). I'm about to migrate everything from one of the old drives to the new drive and see if moving the drive to the other IDE channel will solve the problem (get it off the RAID channel (ide2)).
I don't believe this should happen and I don't know if there is a way to get this thing to work with DMA turned on. That is, I don't know if it is a kernel issue or a hardware issue. The only reason I bring this up is to suggest one more thing to check for all those people who have tried everything else. Of course it would certainly be appreciated if someone has a good suggestion to solve my problem (if moving the drive to the other IDE channel doesn't solve it).