I put together a Tyan Thunder K8W with dual 248s. I put a USB 2.0 PCI card in the PCI-X Slot next to the regular PCI slot and it does not seem to be working. Is there something I need to do to get a PCI card to work in a PCI-X Slot?
Also I plugged a media card reader into another USB 2.0 PCI card that I have in the regular PCI slot and the drive letters show up in Windows Explorer, but when I click on the drive letters, it says "Insert Card" when there is already a card in there (i.e. the reader is recognized, but doesn't read the cards).
Check the homepage of the manufactorer if the cards can operate with 3.3V.
Normal PCI-Slots are 5V slots. PCI-X (and normal 64bit PCI) slots are 3.3V. Normally all not 3.3V cards do not have the needed key to put the cards into a 3.3V slot but SOME have this key but are not build to run with 3.3V.... So they will fit but not function in PCI-X slots. You will have to check the specifications of these cards if they are build for 3.3V PCI.