PCIe extension card for M2 NVME SSD

[fi.bonev]

Hi Everyone,

I just recently started having issues with the capacity of my M2 SSD, and am thinking of expanding.

I have a MSI B450Tomahawk Max. It has 1 M2 slot, which is a bummer, as I rather just buy an extra M2 SSD.
Then it was brought to my attention that I can also get a PCIe extension card, where I can plug my M2 SSD.

My concerns at the moment is what do I need to look out for both in the SSD and the PCIe extension card, as I now see that my motherboard supports the following:

• M.2 slot at PCI-E Gen3 x4
• Apart from my Graphics card PCI-E slot I also have a PCI-E 2.0 x16 slot

My first question is, according to my Google based investigation, since my M.2 Slot is PCI-E Gen3 x4 it will have a maximum bandwidth of 4GB/s.
Would that mean that I am not using the full capacity of the M.2 NVME SSD, when my SSD has reading and writing speeds north of 4 GB/s?

My second question is, I understand that my PCI-E 2.0 x16 slot has a bandwidth of 16GB/s.
I understand that a PCI-E Gen 4 would still work on a PCI-E 2.0 slot, is this correct?
Assuming it is correct, if I have a PCI-E 4.0 x4 M.2 extension card, supposedly with a max bandwidth of 8GB/s, would I be able to make the most out of a M.2 SSD with a read speed of 7.400 MB/s and write speed of 6.500 MB/S (Lexar NM790 2TB M.2 SSD)?

Thank you in advance everyone! Curious to hear your overall opinion
 

[jaslion]

Just get a sata ssd?

 

Not like anything game wise uses the speed.

 

Else well the adapter will just run at a lower pcie speed. Again wont matter for usability

 

[Robchil]

It depends on what your CPU supports too. 

[Electronics Wizardy]

7 minutes ago, fi.bonev said:

My first question is, according to my Google based investigation, since my M.2 Slot is PCI-E Gen3 x4 it will have a maximum bandwidth of 4GB/s.

Yup thats how it works.

 

8 minutes ago, fi.bonev said:

Would that mean that I am not using the full capacity of the M.2 NVME SSD, when my SSD has reading and writing speeds north of 4 GB/s?

My second question is, I understand that my PCI-E 2.0 x16 slot has a bandwidth of 16GB/s.
I understand that a PCI-E Gen 4 would still work on a PCI-E 2.0 slot, is this correct?
Assuming it is correct, if I have a PCI-E 4.0 x4 M.2 extension card, supposedly with a max bandwidth of 8GB/s, would I be able to make the most out of a M.2 SSD with a read speed of 7.400 MB/s and write speed of 6.500 MB/S (Lexar NM790 2TB M.2 SSD)?

You need gen 4 to get the higher speeds, a wider slot won't make it faster as almost all ssds are x4 links.

 

I'd just get a gen 3 ssd. It seems really unlikely that your system will take advantage of the higer speeds.