I have a Dell Precision 670 Workstation. It has 3 PCIX slots (not PCIe) that are supposed to be compatible with PCI. The card currently in the PCI slot (M-Audio Audiophile 2496) would NOT fit in the PCIX slot. In fact, the PCI and PCIX slots don't even line up or look remotely similar.
I want to get an internal wifi card (I don't want a USB dongle) but I'm not sure which cards would fit into a PCIX slot. I have no other open slots available.