ASUS ROG Strix Z790-A M2 slot usage

[wildman]

I am going to be building a new rig soon, however I am massively behind the curve in understadning how most of the new platforms actually work. I was hoping to move to a full M2 storage solution as it's cleaner / less cables etc. Looking at the board below

Asus ROG Strix Z790-A Gaming WIFI (LGA 1700) DDR5 ATX Motherboard

Order Asus ROG Strix Z790-A Gaming WIFI (LGA 1700) DDR5 ATX Motherboard now online and benefit from fast delivery.

www.overclockers.co.uk

questrion I have. If I use all 4 M2 slots on this board will it then gimp the PCIe slot for the GPU to x8 ?

M.2_1 slot (Key M), type 2242/2260/2280/22110 (supports PCIe 4.0 x4 mode)
Intel® Z790 Chipset
M.2_2 slot (Key M), type 2242/2260/2280 (supports PCIe 4.0 x4 mode)
M.2_3 slot (Key M), type 2242/2260/2280/22110 (supports PCIe 4.0 x4 mode)
M.2_4 slot (Key M), type 2242/2260/2280 (supports PCIe 4.0 x4 & SATA modes)

I can't work out if any of them share any lanes with the 1 x PCIe 5.0 x16 slot which is where the 4090 would go


in my ignorance I was guessing no as the PCIe x 16 slot is PCIe 5.0 while the M2 ones were all PCIe4.0

so then assumed (possibly incorrectly), that the only other slots that would be hindered would be the 2 x PCIe 4.0 x16 slot (supports x4 mode)1 x PCIe 3.0 x1 slot

I am not planing on having any other PCIe cards in the system other than an RTX4090 sat in the PCIe 5.0 x16 slot

 

[Tetras]

in my ignorance I was guessing no as the PCIe x 16 slot is PCIe 5.0 while the M2 ones were all PCIe4.0

Yeah, if the Z790 board has PCI-E 5.0 M.2, then it was stolen from the graphics card.

I can't see any conflicts/sharing mentioned in the manual, so I think you're good to load them up. I'll try and do a count, to make sure.

M.2 slot 1 uses CPU lanes: 4 PCI-E 4.0, intended for M.2.

M.2 slot 2, 3 and 4 use chipset lanes: 12 PCI-E 4.0.

There are 2 full length PCI-E slots, with 4 lanes each.

There is 1 PCI-E 3.0 slot, with 1 lane.

Total chipset PCI-E 4.0 lanes used (excluding CPU M.2): 20. Z790 max available lanes: 20.
Total chipset PCI-E 3.0 lanes used: 1. Z790 max available lanes: 8.