Pcie slot 1 only 8x?

[CoolMan]

Lo.
I just got an asus rampage v extreme and i'm having issues with the first pcie slot. It will only run at 8x instead of 16x.

I'm running an intel 5960x cpu with 2 780ti's in slot 1 (pcie_x16_1) and slot 4 (pcie_x16/x8_3) as per the manual.
However the bios says the card in slot 1 is detected, but running at 8x native, but the card in slot 4 runs at 16x.
All power including the ez plug are connected.
And if i run uniengine benchmark it says that the card in slot 1 is only at 324Mhz where the card in slot 4 runs at full speed and my scores are way down because of it.

Even using the dip switch to disable all slots except slot 1 and bios still says only 8x even with all sata drives etc disconnected to avoid sharing.
Any idea on what could be wrong?

[Hopper64]

Look at page 3-35 in the manual. It's Advanced\System Agent Configuration in the bios. NB PCIe configuration. I think some have had to choose Gen 3, but Auto should work. You might try that.

[Chino]

Try reseating your GPU in the first slot. Meanwhile we're diagnosing the problem, remove your second GPU.

Please list your complete system specifications as well.

[CoolMan]

Lo.
Going to try reseting and reflashing the bios later as i did get a corrupted bios screen when i swapped to EZ mode with f7 during setup.
Gen3 isnt listed in the bios menu, just auto, gen and gen 2, but gen 3 was there earlier, just not now?

I'll probably have to swap the gpu's around to ensure the problem is with slot 1 or the gpu, but water cooling makes it a pain,
not even running with the hard drives or pciessd atm to eliminate shared resources as i dont need to actually boot to windows yet as the bios confirms slot 1 is at 8x.

Specs are:
Intel 5960x, rampage v extreme with bios 1401, 2 way 780ti's, intel 750 pcie ssd, 16 Gigs g.skill ripjaws 4 ram,1500watt psu

[Praz]

CoolMan wrote:
Gen3 isnt listed in the bios menu, just auto, gen and gen 2, but gen 3 was there earlier, just not now?

Hello

Need to be looking ion the correct section of the UEFI. That would be NB PCI-E Configuration not PCH Configuration.

[CoolMan]

Praz wrote:
Hello

Need to be looking ion the correct section of the UEFI. That would be NB PCI-E Configuration not PCH Configuration.

Found it, i can set it to gen 3 but first slot still at 8x. I'm going to borrow a vid card to test each slot individually.

[Chino]

Proceed to remove your CPU block and CPU. Verify the CPU socket for any bent or missing pins.

[CoolMan]

K, checled the cpu and mobo pins, all look perfect, but slot 1 still at 8x.

Any thing else i can try before sending the mobo back?

[Chino]

It's probably a wise decision to borrow a GPU to test your system preferrably one thst isn't watercooled. It would save you from RMAing the wrong component.

[CoolMan]

K, tested with a nvidia 670 and still stuck at 8x so the mobo is going back for a refund and i'll try to find an evga classified instead.