I have an Asus P5GDC-V Deluxe MB running WHS. I ran out of SATA ports, and figured I could add a few by plugging a cheap HDD controller into one of the PCI Express slots. The controller I got is x4, and the only slot on the MB larger than x1 is the x16 slot for a GPU.
When I plug the controller into a different computer, the O/S sees it right away and even loads drivers automatically. But with this MB, a card in the x16 slot is not appearing in the BIOS details under PCI devices, and is not recognized by the O/S. It acts as if the card isn't even installed.
In the MB manual it states,
This motherboard supports PCI Express x16 graphic cards that comply with the PCI Express specifications.
under the section for the x16 slot.
Am I SOL? Will this MB simply not accept this controller card? Or is there some BIOS setting I can change to get this working?
I would have thought that PCIe is PCIe, but it appears other vendors are also doing this, where the first/primary/only PCIEx16 slot is for graphics cards only. This seems to be a horrible abuse of the PCIe standard, to include a slot that will not accept PCIe cards. However, since you have determined that the card is working and the manual indicates that the slot is for graphics cards only, I'm not holding out much hope.
Looking through your manual, here are some things you could try (though I doubt they'll work).
Assuming you are using the on-board graphics, do the following on the Chipset page of your BIOS:
- set "Graphics Adapter Priority" to [Internal VGA]
- set "PEG Root Control" to [Disabled]
- set "Slot Power" to [Normal]
You could also try setting "Plug and Play O/S" to [Yes] on the Advanced page, but I'm honestly not sure that will do what I think it will, so I'd skip it personally (otherwise Windows might think you changed your hardware config significantly and crap itself).
I think the only thing I haven't tried is setting PEG Root Control to Disabled. I don't know what that does; the only thing I do know is that when I tweaked one of the several settings relating (directly or indirectly) to the GPU slot, all of a sudden my O/S found new hardware. I'll try that setting and pray.
Asus support has been about as helpful Rhesus monkey. Less helpful, in fact, because occasionally the monkey would do something useful.
Reading the spec sheet on the Intel 915G chipset, Intel talks about the port being usable for a graphics adapter card or an ADD2 card (basically a card to add a second video output to the IGP). Nothing about using the port for other purposes.
According to an ASUS support rep, the P5GDC-V Deluxe will only support GPU cards in the x16 slot because "there is only one slot, so it is intended for graphics".
I am not convinced that the rep researched this at all. Even after I told him the product name, he didn't seem to be aware of the number of x16 slots (he spoke of using "either" slot) until I told him. And at that point he recanted a previous statement that, "yes, it should work," and replaced that with, "No, if there is only 1 x16 slot then it is for graphics. This is even the case when the MB has an IGP."
Basically, this was about the worst "support" possible: willfully giving out unconfirmed "facts" without bothering to verify anything. I have worked in the support industry. In my team, we considered ourselves to be the customer's "last, best hope." If we failed them, they failed. So we made it a point to try to be as accurate as possible, and not give them misinformation. I wish Asus Support were more interested in doing the same.
So, "officially", ASUS does not seem to support a non-GPU card in the X16 slot on the P5GDC-V Deluxe. And apparently that's about the best answer I'm ever going to get, unless Intel speaks up with info about the 915 chipset.