[SOLVED] Understanding PCIe slots

[Industromaxx]

I have a 5950x on an Asus X570 Crosshair 8 Extreme. I have four gen 3 M.2s on the board, 2 of them aren't detected due to not enough lanes as the 5950x supports 24 lanes. If I were to use an expansion card for the 4 M.2s and put them in a x8 slot, would it cause my x16 slot (which my gpu is in) to split due to the website saying x8/x8? Furthermore, if the expansion card is in an x8 slot would each M.2 run at x2? If that's the case, if I were to put the 4 m.2s in raid, would it make up for the performance loss?

 

[CountMike]

I have a 5950x on an Asus X570 Crosshair 8 Extreme. I have four gen 3 M.2s on the board, 2 of them aren't detected due to not enough lanes as the 5950x supports 24 lanes. If I were to use an expansion card for the 4 M.2s and put them in a x8 slot, would it cause my x16 slot (which my gpu is in) to split due to the website saying x8/x8? Furthermore, if the expansion card is in an x8 slot would each M.2 run at x2? If that's the case, if I were to put the 4 m.2s in raid, would it make up for the performance loss?

Two last M.2 slots are only SATA so NVMe wouldn't work in them. That leaves you with only 3 NVME slots available,

 

[USAFRet]

if I were to put the 4 m.2s in raid, would it make up for the performance loss?

NVMe + RAID 0 often results in slower user facing performance vs individual drives.
Seriously.

Benchmarks can look great.
Actual performance, not.

 

[Industromaxx]

Two last M.2 slots are only SATA so NVMe wouldn't work in them. That leaves you with only 3 NVME slots available,

Do I have the right idea then about the x16 slot then becoming x8 because of installing an expansion card into the x8 slot?

 

[SkyNetRising]

I have four gen 3 M.2s on the board, 2 of them aren't detected due to not enough lanes as the 5950x supports 24 lanes.

What model M.2 drives are you using?

 

[SkyNetRising]

Do I have the right idea then about the x16 slot then becoming x8 because of installing an expansion card into the x8 slot?

Yes.
With PCIE card installed into second PCIE x16 slot, both PCIE x16 slots switch into x8 operation mode.

 

[Industromaxx]

Yes.
With PCIE card installed into second PCIE x16 slot, both PCIE x16 slots switch into x8 operation mode.

Alright thank you, the 4 M.2s I'm using are the 2tb 970 evo plus

 

[SkyNetRising]

Alright thank you, the 4 M.2s I'm using are the 2tb 970 evo plus

To install 4 M.2 NVME drives on your board, you have to switch PCIE x16 slot to x8 operation mode. There's no other way.
Then you can use 3 M.2 slots on board and plus 2 M.2 slots on DIMM.2 card (5 NVME drives total).

If you absolutely need PCIE x16 slot to be in x16 operation mode, then you can have max 3 NVME drives -
one in M.2_1 and two in DIMM.2 slot.

 

[Industromaxx]

To install 4 M.2 NVME drives on your board, you have to switch PCIE x16 slot to x8 operation mode. There's no other way.
Then you can use 3 M.2 slots on board and plus 2 M.2 slots on DIMM.2 card (5 NVME drives total).

If you absolutely need PCIE x16 slot to be in x16 operation mode, then you can have max 3 NVME drives -
one in M.2_1 and two in DIMM.2 slot.

Alright, appreciate the help.