The case of the vanishing GPU

[iamthewindrider]

So I decided to rebuild my right from a phenom II to the specs listed below:
Motherboard: Gigabyte990FXA-UD3
Processor: FX-6300 Six-Core 3.5GHz AM3+ Processor - AM3+, Six-Core, 3.5GHz, 14MB, 95W, Unlocked
RAM: 32 GB DDR3 (4x8 GB)
PSU Thermaltake TR2 TR-700w
2X GPU EVGA GTX660 3GV
Operating System Windows 8.1
Driver: 334.89

while I had working SLI previously, I just wanted more juice and better graphics you know the story. I'll turn on the Computer, windows is fine, device manager shows 2 GPUs but no SLI options in the Nvidia control panel. I reboot, the second GPU has disappeared.

There's ample power for my setup (700 watts), and the 2nd card works

I have swapped it with the the GPU in the first slot and it works fine., (so there is no damage to the 2nd slot).

No errors in the event log, the computer acts like removed the second GPU.

Any suggestions or thoughts?

What on earth is going on here!?

 

[smeezekitty]

Do both PCI-E slots work?
Did you change the motherboard when you upgraded?

edit: it appears you tried the slots already.
If you did change the motherboard, did you reinstall win?

 

[iamthewindrider]

Do both PCI-E slots work?
Did you change the motherboard when you upgraded?

edit: it appears you tried the slots already.
If you did change the motherboard, did you reinstall win?

I did.Yes. to no avail.

 

[iamthewindrider]

Do both PCI-E slots work?
Did you change the motherboard when you upgraded?

edit: it appears you tried the slots already.
If you did change the motherboard, did you reinstall win?

Are there any BIOS changes that are required (my motherboard has a UEFI Dual Bios).

 

[iamthewindrider]

Update this has been resolved. My motherboard has 2 x PCIe 2.0x16, 2x PCIe 2.0 x 4.0 x1 they are staggered. Using the two 16s turned on my SLI capability!