I have an Adaptec AHA-2940UW SCSI hostadapter to which I connected a single Atlas 10K III drive (and nothing more).
When my computer powers up it shows POST and then the option ROM from the Adaptec HostAdapter. Here 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 multiple LUN support is disabled in the Adaptec's BIOS (via the SCSI-Select utility)