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Context:

I have an Intel DX79TO motherboard and a Sun SAS3081E-S/LSI 1060E-S HBA card with a PCIe x8 interface. I plug the HBA into my mobo next to my graphics card, and the HBA power lights illuminate, but the BIOS and OSes (tried Linux, ESXi, Win7) don't see the HBA at all.

Question:

Does the DX79TO motherboard support non-x16/non-GPU devices in its PCIe x16 slots? According to this question, some consumer motherboards don't support this, but I can't figure out whether or not this motherboard/family does. The answer will affect whether I buy a new motherboard or RMA the SAS card, with money attached to each course, so I figured I'd ask here first.

What I've Tried:

I've read the spec/manuals for the motherboard and the HBA, and I didn't see anything regarding whether or not the x16 slots were back-compatible to lower lane widths/non graphics-card devices, or whether or not the card could run in wider slots than x8. I've tried contacting Intel, but that was over a month ago and I haven't yet heard anything back except an automated "we got your email!" message.

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You are correct that some boards do not accept this. I was having huuuuge problems with a RAID card in a Gigabyte board. Further research indicated that the top PCI-E x16 slot could only be used for graphics cards. Moved it into one of the other PCI-E slots, and hey presto, started working immediately. –  Mark Henderson Jul 9 '12 at 2:32

1 Answer 1

up vote 3 down vote accepted

The PCI Spec specifies that any combination may be used in slots/cards and must work (though the slot does not have to physically accommodate larger cards). Thus per the spec an 8x card must work in a 16x slot. It's possible your specific board is non-compliant (though highly unlikely); if it's non-compliant it's probably a bug in the card or BIOS.

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Verified on this particular board: both x16 slots will work with x8 cards. –  Zac B Sep 27 '12 at 12:18

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