PCIe x4 slot not working on Gigabyte UP5 TH

[eyelight]

I built the following system and recently added the second GPU (the 680), and now the PCIe x4 slot doesn't work. I hadn't used that slot previously, as the High Point card was moved from the x8 slot to the x4 slot to accommodate the new GPU.

Gigabyte GA-Z77X-UP5 TH
Ivy Bridge 3.5Ghz Quad i7
32GB Ram
240GB SSD boot drive
4x 3TB 7200 Seagate HDDs in Raid5
EVGA GTX 580 (x16 slot)
EVGA GTX 680 (x8 slot)
High Point 2720 Raid card (x4 slot)
850w Corsair Power supply
MacOS X 10.8.2

Does anyone have any idea why this slot would not be working?

I've tried unplugging the Thunderbolt devices, as I thought maybe Thunderbolt was taking PCIe bandwidth and disabling the x4 slot. No luck.

I noticed the motherboard says that the x4 slot is only enabled when an Ivy Bridge CPU is used. I am indeed using an Ivy Bridge CPU, but wondering if there's anything else I need to do to enable it. BIOS?

Do I need to do anything in MacOS to enable this slot? My system thinks it is an iMac 12,2. Should I change this to Mac Pro 3,1 or something like that?

Thanks for any insight!

 

[Xmephestox]

did you ever get this resolved? my 4x slot doesn't work either. but I think it's a mobo issue nothing to do with the os. I have a HBA card in the 4th slot, and if the mobo recognized it I would see it initializing in bios and it doesn't. wondering what motherboard setting could activate that slot

 

[eyelight]

No I haven't figured it out yet. Good to know others are having the same problem and its not necessarily a defective motherboard.

 

[FishCow]

Did you plug in the extra auxillary power to the PCI - it's a SATA Power connector on the front of the board - (ATX4P)
I seem to remember Gigabyte recommends if you use two graphics cards + - then the PCI needs more juice.
I don't know if this will make the x4 slot work - but worth a shot if you haven't tried it already
Good luck
Fish

 

[eyelight]

The secondary power connector is indeed connected. I have now even taken out both GPUs and only have the raid card installed, in the x4 slot. Still no luck. I've opened a ticket with Gigabyte support. Their response so far was that it should be plug and play.

 

[PJALM]

Are you sure that card works in a 4x slot? It is after all a 8x card. Also the TB ports do in fact take some of the PCIe lanes. You may want to try disabling it completly in your bios.

 

[eyelight]

I just tried a different card in that x4 slot, and with two other cards, the third slot worked.

Looks like that card needs an x8 slot to function.

 

[flmmkr]

I'm having the same issue. I have a GTX Titan in the PCIEX16 slot, Red Rocket in the PCIEX8 slot, and Atto H680 HBA in the PCIEX4 slot, and the H680 won't work. Atto says the H680 should still work in an X4 slot. Gigabyte says there's no settings because the PCIE slots are managed by the CPU.

I have a Blackmagic Design Decklink card that works in the slot with no issues. I normally want to have the Decklink card in a Thunderbolt enclosure (or get an UltraStudio 4K). The H680 still won't work in the Thunderbolt enclosure. Remove the Red Rocket and the H680 works in the PCIEX4 slot and the Thunderbolt enclosure. I'm also able to have the Red Rocket, Decklink, and Red Rocket in Thunderbolt enclosures, which are basically x4) and they'll work with my MacBook Pro Retina with no issues, except slower than I'd like.

It's been suggested to try swapping the Titan and Rocket. I also have 2 PCIEX1 cards installed and will remove those for troubleshooting. It was also suggested to remove my overclock and to even try underclocking. I haven't had a chance to try any of that yet because of work.

Does anyone have any thoughts to what's happening here? Seems like some kind of issue with RAID and HBA cards mixed with certain other types of cards. I was considering buying a different card like a Highpoint or Areca, but it sounds like it won't help.