MB only uses 8 lanes out of 16

[shtoq]

As my previous issue was solved nicely I'd give my other issue a go. Here is my setup:

Core i7 2600K + Scythe Mugen3
GIGABYTE GA-Z68A-D3H-B3
Corsair TX750M
MSI N560GTX-M2D1GD5
OCZ 120gb Agility3
X-fi Titanium
Windows 7 professional

When I check CPU-Z and Aida64, my motherboard seems to be using only 8 of the 16 lanes available lanes on my 560GTX. I don't have anything installed in the lowest 16x slot and have only one PCI-e slot occupied besides the GPU. I have plugged my X-Fi card in the pci-e 1x slot closest to the CPU.

Can anyone tell me if this is correct? I did set my bios to use the GPU in the 16x slot so it does not seem to be a setting in there.

Anyone know the issue and a possible solution (if any exists) for it.

 

[hang-the-9]

Not all 16x physical slots are 16x electronically. Check if the slot you have the card is is actually 16x.

 

[shtoq]

How can I check that?

 

[hang-the-9]

How can I check that?

Manual for the motherboard should tell you.

 

[mathew7]

Move your GPU to the top PCIe x16 slot. It should say in the manual: if using just one GPU, put it in the 1st x16 slot.
Reason: 1st x16 slot has 8 lanes connected directly and another 8 lanes through a switch. That switch decides if the lanes go to the 1st slot (forming x16 for 1st and x0 for 2nd) or 2nd slot (so only the direct x8 in 1st and x8 to the 2nd). By placing the GPU in the 2nd, you have entered the x8+x8 configuration, regardless of 1st slot content. Note, I'm talking about the x16 slots. So it's actually the 2nd and 4th slots according to the MB image.