pci slots question

[Cl1362]

i have the asus crosshair vi hero.

 

it has 3 pci slots.

i am thinking of getting the meshify c. and id  like to put the gpu on the bottom pci slot.

i saw online that it has a PCIe 3.0 x16 (CPU): 2 (x16/x0, x8/x8) on the asus board.

 

im not very familiar with that x16/x8 meaning. but im assuming its half of the performance. however for gaming would it be a huge difference in performance?

 

or is there a way to disable the top lane to make the middle or bottom lane to run x16?

 

thanks in advance

[ShredBird]

There is not a significant deterioration of performance using x8 instead of x16.  You may be able to set the speed in the BIOS/UEFI or it may auto configure based on how many devices are present, just depends. 

[Cl1362]

Just now, ShredBird said:

There is not a significant deterioration of performance using x8 instead of x16.  You may be able to set the speed in the BIOS/UEFI or it may auto configure based on how many devices are present, just depends. 

thank you!