Asus X470-F Mobo. Using second M.2 disables PCIEX slot

[hifihigh]

Hi, I am trying to dual boot so I put an old M.2 NVMe disk in the second slot on this motherboard, but now the wireless LAN card I had installed in PCIEX1_3 doesn't work. It's not a big deal because I use wired LAN 90% of the time but it would be nice to have it working. I can't use the first two mini PCIEX slots as they're covered by the heatsink on the graphics card.



I found a setting in the bios, PCIEX16_3 4X-2X Switch that lets me enable either or. If I set it to Auto or 4X, the computer sees the M.2 slot but not the wireless card. If I set it to 2X then windows can see the wireless LAN card, but not the M.2 NVMe storage device.

Is there a way to have both? I was thinking maybe I could move the Graphics Card to PCIEX16_2 then put the wireless card in PCIEX1_1. Would that have a performance hit on the graphics if the card is not in the main PCIEX16 slot?

[xeny]

Have a look at the table on page viii of https://dlcdnets.asus.com/pub/ASUS/mb/SocketAM4/RO...

specifically the section "expansion slots".

Essentially you're running out of PCie lanes.

It looks as if you can split the x16 PCIe from the CPU in half between the 1st and 2nd x16 slots There's would be some impact (we're halving bandwidth) but without benchmarking it's hard to know if it would be perceptible in the games you play.

Could you put the wireless card in the x16_3 slot? That would leave you with full bandwidth to the GPU.

Reading the first section of page 32 of https://dlcdnets.asus.com/pub/ASUS/mb/SocketAM4/RO...

my interpretation is with the 2nd M2 slot in use, you'd get x4 mode on the 3rd x16 slot, which should be ample for a wireless card?

Alternatively, do you have an old SATA SSD for the 2nd OS?

[hifihigh]

Thanks, I did not realize smaller PCIE cards would work in physically larger slots.

I'll try the wireless card in the PCIEX16_3 slot tomorrow.

[hifihigh]

Just wanted to say thanks xeny, it worked!

I woke up early and couldn't get back to sleep so I had a go at putting the wireless LAN card in the last PCIEX16_3 slot. Now the computer can see both the wireless card and the disk in the second M.2 slot.

Cheers!