Slot 2 and 4 is pcie x16 physically. Both slots are able to run at pcie 3.0 x16 only if one of the slot is used. If you use both slot 2 and 4, they both run in X8/X8 mode.
Slot 2 and 4 is pcie x16 physically. Both slots are able to run at pcie 3.0 x16 only if one of the slot is used. If you use both slot 2 and 4, they both run in X8/X8 mode.