Board integrated features use my PCI lanes?

[GameRat]

Hello all,

Need to get this out my head already... Let's say I have a board with 10GigE, dual Wifi, Thunderbolt, etc., and a 7900X with 44 PCI lanes. Generally, will I still have my 44 lanes available if I use this board?

Thanks,

 

[Aeacus]

Short answer: Yes.

Long answer:
CPU provides PCI-E lanes for x16 slots and M.2 slots. For other PCI-E slots, e.g x1 ones, the PCI-E lanes are provided by MoBo's X299 chipset. Latest Intel Core X CPUs can have up to 44 PCI-E lanes while X299 chipset can have up to 24 PCI-E lanes.

In other words, as an example with 3 GPUs and one M.2 in the system: 1st and 2nd GPU can run with 16 lanes, while 3rd GPU runs with 8 lanes, leaving 4 lanes for M.2 SSD. For all other components that are also using PCI-E lanes, e.g dedicated sound card in PCI-E x1 slot, those PCI-E lanes are provided by X299 chipset.

To give you an idea, here's a PCI-E lanes layout on Asus X99-A MoBo,
image: