Build Your Own NAS, part two.: Page 2 of 2

Next I went to install the storage that Adaptec/Maxtor sent me. Pretty sweet system, with a drive bay, four SAS disks and an Adaptec 4800SAS controller. Unfortunately, the 4800 does not appear to be PCI compatible. I tried slipping it in, and the controller won't go in the expansion slot unless I take of the mounting bracket and reverse the card. Due to dimension issues, that would involve rotating the motherboard such that the back connectors no longer face out the back of the box. Bad JuJu. But not an impossible task. This is akin to prototyping, and I've done more ridiculous things prototyping.
But I've also blown a component or two by assuming too much. So I set about researching the card and its interfaces. I also delved into some competitors' cards as reference points.
My research shows that even though the standard says that PCI-X is backward compatible to PCI, most controller vendors have at least one card that isn't. Caveat Emptor apparently, for the vendors I looked at never say "this is not PCI compatible" in an upfront manner. I ended my research with the impression that the card I received - the 4800SAS is not PCI compatible, but the 48300SAS is. I hope I'm wrong, but that's what it looks like.

I've got a note out to Adaptec asking them if my research is correct - is the 4800SAS not compatible. No big deal if it isn't, I've got a machine here with plenty of PCI-X slots, not as cool as "buid your own SAS-based NAS", but still mondo cool IMO.
I'll keep you posted. If it's not PCI compatible, I'm going to either (a) Pick up some SATA disks to string off the motherboard's built-in SATA controllers or (b) get an old EIDE array controller card and string my collection of IDE disks off of it in an attempt to build an array. Either way it should be fun, but I'm hoping that the SAS controller really is PCI compatible.