I have an Adaptec AHA-2940UW SCSI adapter, to which I connected a single Atlas 10K III drive (and nothing more). When my computer loads up, the pre-OS Adaptec screen shows (I believe this is called the POST screen), where I can see the Atlas drive listed many times (i.e. with ID0, ID1, ... ID5, ID7, ID8,...,ID15 [ID6 is the adapter itself])
Using the same HD on an Adaptec AHA-2940UB the disk only shows once
Since my OS hasn't been installed yet, I'm not sure if this is a problem (I would guess it is), and if so - how to solve it.
Termination and multiple LUNs come mind, but the cable provides termination and I don't see why a hard drive would request multiple LUNs, especially considering it is not jumpered at all, and multuple LUN support is disabled in the Adaptec controller BIOS (via the SCSISelect utility)