PCIe , M.2 question

Vetifer · May 16, 2023

I currrently have a msi x370 gaming pro carbon motherboard and recently ran into some troubles. I have a 6900xt graphics card in my top pcie slot (#9 in the picture) i have a 1tb M.2 in the top most m.2 slot (#10) Then i have a second graphics card i use for just streaming in the very bottom pcie slot (#12) i keep it in this slot because if i were to use the #11 slot the second graphics card sits very close to the 6900xt making the card run a little warmer then i like. So having the second graphics card in the bottom slot helps. This was never a problem till i recently bought anther M.2 and put it in the bottom slot (#10 bottom) and by doing this it uses the bottom most pcie lanes , making the graphics card not work in that slot anymore. So what im wondering is, is there anyway i can make my new M.2 use the lanes from a different pcie slot? Or am i stuck having to move my second graphicss card up to the #11 spot ?

CyberneticTitan · May 16, 2023

It's not possible to "use PCI-E lanes from a different PCI-E slot". The allocation of PCI-E lanes for that particular motherboard on that second M.2 slot is either using that M.2, or disabling that lowermost PCI-E x16 slot and SATA3.

So, some options to have everything is to:

Move that lower GPU to the middle x16 slot and put that NVMe in the second M.2 slot.
Find a PCI-E x4 to M.2 adapter such as https://www.startech.com/en-ca/hdd/pex4m2e1 and put that in the middle x16 slot
Find a PCI-E x1 to M.2 adapter and use it any of the x1 slots, although you will have reduced NVMe speeds
Use an external enclosure for that NVMe and plug into one of the USB 3.1 Gen2 10Gbps ports on the back. Will likely also reduce your SSD speeds.