I looked it up for you. The Asus p4s333 series has two ide ports (aka ide channels) and therefore will support up to four drives, two on each cable, one cable attached to each port. Transfer modes up to UDMA 100.
If you need more than that SIIG inc. (and others) make pci cards that let you add four more drives for a maximum of eight which as I recall is the limit allowed for ide. Any more than that and you'll have to go scsi.
Hope this clears it up for you.
