SLi does not engage (2x GTX780-DC2 on Maximus VI Hero)

[Pacifi3r]

Hey guys,

first post here and happy to join you, although the circumstances could be a bit more positive.

Having trouble with my brand new system, got it yesterday. Other than the stated components it runs W8.1 64 on an i7 4770K, 8 GB Corsair DDR3-1600 RAM. The issue here is that neither the BIOS (AMI, Rev 1505) and subsequently nor the nVidia Driver/Control Panel detects the second installed GTX780.

I updated all the drivers for the MoBo, checked the power source (LEPA, 1200 watts - also interchanged cables and tried splitting up the power support with an additional cable from the power unit to the GPUs, made no difference), interchanged the GPUs in their slots, installed either one or both SLi-connectors/bridges (soft ones) in every possible variation (but always "in line") ... but still: NO SLi and no detection by the BIOS

What really bugs me is, that even the BIOS states the second PCIe device as "not present". Both GPUs do work flawlessly when inserted in the primary (16x) slot, but the one inserted into the secondary red PCIe-slot always appears to be undetected by the system. I do always get the green LEDs on each card, both cards have their fans running though the heatpipe on the 2nd (lower) card remains cold, so it's obvious that this card remains completely idle.

For now I am a bit out of clues here so any thoughts/ideas are greatly appreciated. Hopefully I'm just too blind to see something I missed, otherwise I'm quite afraid that there's some major fault on the MB.

Cheers,

Ben

[MatsGlobetrotter]

Hi,And you have connected the external extra power cable on both cards? They are all requiredWhat does the pcie bios state x16 or x8 on the first port and does it show completely undetected on the second or does is show x1or something else on the second port.

[Pacifi3r]

Thank you Mats for your quick reply. Yes, both cards are fully powered via the additional plugs, everything in place. The BIOS states x8 (Native) for the primary slot, x16 for the second and/but "not present", which - as I get it - says "single GPU"-configuration of the MB, since it would convert to 2x x8 with both GPUs detected.

EDIT: 1st slot status amended

[Pacifi3r]

PROBLEM SOLVED: The mainboard has been replaced with the Maximus VII Hero. Now runs stable and smooth.