Question about PCIe Adapter Card for M.2's

[Vivelric]

Hello everyone, apologies if this doesn't make much sense. I'm not very technically inclined on the finer details and such.

 

So I recently built a new PC and on my motherboard it has 2 slots for M.2's. Both are populated now with some Samsung 970 evo's and I may need more storage soon.

I don't have any more slots on the motherboard so I was looking into something like a PCIe Adapter Card (I think that's what they are called) because I don't wanna really deal with SATA.  

Would installing one of those with a an M.2 hurt performance in any way since it'll be on the PCIE?
Like would it suck any bandwidth performance from the GPU or would the M.2 have slightly less read and write speeds since it would have to go through the PCIe?

Thanks in advance!

[spartaman64]

a gpu uses x16 pcie lanes a m.2 ssd used x4 pcie lanes a r5 3600 has 24 pcie lanes so you can put in 2 m.2 ssds before potentially taking away lanes from the gpu. the motherboard chipset also has some pcie lanes so you could have be able to put in more 

edit: apparently 4 of the lanes are reserves for the chipset so you only can use 20 of the lanes from the cpu 

[MartinIAm]

16 minutes ago, spartaman64 said:

a gpu uses x16 pcie lanes a m.2 ssd used x4 pcie lanes a r5 3600 has 24 pcie lanes so you can put in 2 m.2 ssds before potentially taking away lanes from the gpu. the motherboard chipset also has some pcie lanes so you could have be able to put in more 

edit: apparently 4 of the lanes are reserves for the chipset so you only can use 20 of the lanes from the cpu 

And then you have another 4 lanes dedicated for the two m.2s that he has on the motherboard, so you would have to split the gpu's lanes in 8x so it can provide 4x to the pcie card for the extra m.2s.

[Vivelric]

For reference I have the ASUS ROG STRIX Z490-E.

Safe to assume I'm at max lane usage then?

[NewMaxx]

Everything goes over the chipset on Intel boards. You can add a M.2-to-PCIe connector in the third long PCie slot which goes over the chipset for a third drive, but it's sharing bandwidth with the other two drives that are also over the chipset. I haven't studied up on Z490 much but if it's like past Intel boards this will be limited but only when the drives are used simultaneously.