yes u can use that slots.
this depends on each boards. not all boards definitely gives u x8 x8 configurations as such is because of SLI requirement. but mostly is only x16 x4 configurations. beside that not all gpu really uses up to x16 capability.
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damn all these lane theory im not that good at it but this is what i tell u.
1st pcie lane x16 will be a 3.0 type with the lanes taken by cpu (or u can say provided by the cpu)
then some things like another x16 lane or x1/x2/x4 lanes depends on the motherboard.
so here is an example for u. :
lets say u buy this mobo : ASUS B150 PRO GAMING AURA
their specs: Expansion Slots
1 x PCIe 3.0/2.0 x16 (x16 mode, )
1 x PCIe 3.0/2.0 x16 (max at x4 mode) *1
2 x PCIe 3.0/2.0 x1
2 x PCI
*1:When PCIE x16_2 is occupied by x4 or faster devices, PCIE x1_1 and PCIE x1_2 will be disabled. (PCIE x16_2 is actually the gpu slots)
this is because board like B150 max lane able to provide 18 so a few of the lanes is given to other ports and support so u cant use other lanes beside PCI.
more details on system lanes :
https://www.pugetsystems.com/labs/a...-B170-Q150-Q170---What-is-the-Difference-635/
