Question Card supports PCI-E 16x 2.0, but running PCI-E 8x 2.0

[OfficeMatti]

Hello!
So i looked up GPU-Z today and i noticed that my graphics card is curretly running on PCI-E 8x 2.0 instead of PCI-E 16x 2.0, GPU-Z also says that my graphics card supports 16x 2.0.
My GPU is in the first slot, runned Render test and it changed from PCI-E 8x 1.1 to 2.0.
I dont know if theres big difference between 16x and 8x, but it would be nice to fix this "problem" and get this to 16x 2.0.
My PC specs:
Intel Xeon X5650
Intel X58 MOBO
8GB ECC/REG DDR3
Palit GTX 680 Jetstream 2gb
500w PSU
500GB HDD
Windows 10 Pro 64-bit
And what do you guys think? Is there big diffrence between those two?
If you need more information about this, just ask!
Thank you in advance!

 

[Lutfij]

Make and model of your PSU and it's age? Latest BIOS for your X58 motherboard? Which OS are you working with on this platform?

 

[OfficeMatti]

Make and model of your PSU and it's age? Latest BIOS for your X58 motherboard? Which OS are you working with on this platform?

Make and model of your PSU and it's age? Latest BIOS for your X58 motherboard? Which OS are you working with on this platform?

Thank you for your respond! I know about my PSU that its Seasonic and it has 500w. And yes, i have lates BIOS. Im using Windows 10 Pro 64-bit