Question RTX 3080 PCI-express x8 and not 16

[Ysmir-m]

Hello I recently purchased an RTX 3080 and I'm having some trouble with it. When I open up device manager or GPU-Z it says that my graphics card is using PCI-express x8 3.0 and not 16. I don't really know how much I should care about that or how much performance I'm loosing so I would really appreciate some help.

Things I've tried so far:
updated my bios.
removed and reinstalled the graphics card drivers.
used 2 different cables instead of the one that splits into 2 and reseated my graphics card.

Specs:
ASUS ROG STRIX B450-F GAMING
MSI GeForce RTX 3080 10GB VENTUS 3X OC
AMD Ryzen 7 2700X Processor
Corsair Vengeance RGB DDR4 3000MHz 16GB
Corsair TX750M, 750W PSU
Samsung 860 EVO 500GB SSD
WD Black SN750 NVMe SSD 1TB M.2 with Heatsink

 

[sizzling]

Is the gpu in the pcie slot nearest the cpu?

 

[Ysmir-m]

Is the gpu in the pcie slot nearest the cpu?

Yes

 

[dotas1]

Press the question mark next to the bus interface in GPU-z and run the stress test. Does it change to x16?

 

[Ysmir-m]

Press the question mark next to the bus interface in GPU-z and run the stress test. Does it change to x16?

Nope

 

[dotas1]

Go to BIOS then Advanced->Onboard Devices Configuration-> PCIEX16_3 and change it from Auto

 

[Ysmir-m]

Go to BIOS then Advanced->Onboard Devices Configuration-> PCIEX16_3 and change it from Auto

Sorry for the late response tried that just now and it didn't work either