Asus P4C800 Deluxe - Manual (Page 42)

2-16 Chapter 2: Hardware information
2.6.3 PCI slots
There are five 32-bit PCI slots on this motherboard. The slots support PCI
cards such as a LAN card, SCSI card, USB card, and other cards that
comply with PCI specifications.
1. The PCI 5 slot and the Wi-Fi slot may not be used at the same time.
2. When installing long PCI cards, it is recommended that you install
them in PCI slots 1, 2, or 5. Long PCI cards installed in PCI slots 3
and 4 may interfere with the SATA and GAME connectors.