My cpu pcie lanes

[devingericke]

Hi I’ve done some research before posting this but still in a bit of a trouble i have an Z370 sli plus mobo and an intel i7 8700K processor with 16 pci express 3.0 lanes but i also have an with an samsung 960 EVO 250GB NVME ssd that uses 4x pci-e (3.0) lanes ... my mobo’s manual says that the m2 slots are conected to my cpu so that means it uses the cpu lanes so i was wondering i want to buy the Gigabyte Radeon RX 580 Gaming 8GB GPU and my mobo has 3 pcie slots ons that does pcie x16 (3.0) , pcie x8(3.0) and an pcie x4(3.0) but i was wondering if i use the x16 slot will it limit itself to only x8 lanes or will i have to put it into the x8 lane from the beginning and what difference does x8 make instead of x16

 

[Lutfij]

Based off what I'm reading from your motherboard manaul, it states the M2_1 will rely on SATA ports which is why that populating the aforementioned M.2 slot will negate the functionality of SATA ports 5 and 6. You'll be fine with your GPU in the first slot and the SSD in the first M.2 slot.

 

[Rogue Leader]

Hi I’ve done some research before posting this but still in a bit of a trouble i have an Z370 sli plus mobo and an intel i7 8700K processor with 16 pci express 3.0 lanes but i also have an with an samsung 960 EVO 250GB NVME ssd that uses 4x pci-e (3.0) lanes ... my mobo’s manual says that the m2 slots are conected to my cpu so that means it uses the cpu lanes so i was wondering i want to buy the Gigabyte Radeon RX 580 Gaming 8GB GPU and my mobo has 3 pcie slots ons that does pcie x16 (3.0) , pcie x8(3.0) and an pcie x4(3.0) but i was wondering if i use the x16 slot will it limit itself to only x8 lanes or will i have to put it into the x8 lane from the beginning and what difference does x8 make instead of x16

The motherboard chipset has 24 PCIe 3.0 lanes on its own for system devices. The M.2 slots run on those lanes. I looked at the manual to see where it says it uses CPU (as it would be a first for this type of board) and it says nothing about the M.2 slot using CPU PCIe lanes. If somehow it did, then the board would not support SLI. Only X99 or X299 motherboards on the Intel side have M.2 slots that go to the CPU.

The 16 lanes on your CPU are reserved for GPU slots.