Showing results for 
Search instead for 
Did you mean: 

ASUS ROG Strix Z790 E Expansion slots

Level 11

Hi all,

 It's been a while since I have been active here, after my x79 build....

    I think I know the answer but looking for reassurance,

    Please read bellow following the images.

Z790-chipset-blockdiagramZ790-chipset-blockdiagramMotherboard layoutMotherboard layout

    If I was to populate slot (3) PCIEX16(G5) and populate (6) M.2_2(SOCKET 3),

    will the  Graphics Card in PCIEX16(G5) still run at 16x lanes bandwidth ? 

    as the  M.2_2(SOCKET 3) is 4X lanes dedicated to the CPU.

    I would like to populate all four lower Sockets M.2_2, M.2_3, M.2_4 and M.2_5

    in a Raid configuration, hoping this suggestion would not affect the Graphics Card

   Running at 16X lanes.

   After doing some research I feel I should leave M.2_2 empty as this would leave

   4 free  lanes for the CPU.

   Having 3 X m.2 NVMe SSD's would work fine in say : RAID 1 or 5.

   Looking forward to seeing every ones responses.

  Kind Regards, Be Safe,



Level 16

I think this video might be helpful:

I just copied the link from the other thread about this here:

Oh, hold on, I was just about to give credit for the link and you provided it yourself! lol 

Sorry that I don't know enough about this subject to give a definitive answer....

Z690 Hero, BIOS 2703, MEI 2316.5.0.0, ME Firmware, 7000X Case, RM1000x PSU, i9 12900K, ASUS TUF OC 3090TI, 2 x 16GB Corsair RAM @ 5200MHz, Windows 11 Pro 22H2, Corsair H150i Elite AIO, 4x Corsair RGB fans, 3x M.2 NVME drives, 2x SATA SSDs, 2x SATA HDs.
Today We're Answering a Subscriber Question! The ASUS ROG Strix Z790 E Gaming WiFi Motherboard Overview of Slots and Storage for PCIe Resource allocations! The Specifications will be Our Outline. Using Four pieces of Documentation this time, Motherboard Manual, Bios Manual, ASUS Thunderbolt 4 card

Level 8

I think it is M 2.1, not M2.2 that you want to leave unpopulated. If I have the correct manual, the below is stated. Unfortunately, I can't find that FAQ. 

"Please check the PCIe bifurcation table
on the support site (
* When M.21 is occupied with SSD device, PCIEX16(G5) will run x8 only.
To ensure compatibility of the device installed, please refer to for the list of supported peripherals."

Level 11

Hello Sworcester, thanks for your response.

I did download the Strix Motherboard owners manual, and from my understanding,

you are correct.

I might be overthinking it, just wanted to be sure.

It would be great to know if by using all cpu lanes

ie : Graphics Card using 16 x  CPU lanes

and M.2_2 Using using 4 x Lanes dedicated to the CPU.

Would this configuration have a negative impact of the Cpu


I'll have to do some more research!


M2_2 isn’t off the CPU, M2_1 is, so M2_2 won’t slow down the PCIEX16(G5)