I get the feeling we might understand the term interface differently. What do you take it to be? To me, the interface is PCI-Express 4.0 4x. The "1950 MB/s write and 4700 MB/s read" are the specifics of the drive's performance.
According to Wikipedia, PCIE 4.0 4x can sustain more than the spec sheet advertises [0].
The spec sheet advertises 4700 MB/s write and 1950 MB/s read. The interface can handle more than 7000 MB/s in each direction. That's more than twice the advertised bandwidth of this drive.
If what you mean is that the MP600 isn't able to handle the claimed 4700 MB/s "most of the time" or something, than that's fair (I have no idea if that's the case or not). But the "interface" doesn't really come into play, here. The drive is advertised as PCIE 4.0 4x because the 3.0 revision couldn't handle the advertised maximum read specs.
Just like it would seem strange for an internet provider to sell a 400 Mbps (advertised) connection over a 100 Mbps line.
According to Wikipedia, PCIE 4.0 4x can sustain more than the spec sheet advertises [0].
The spec sheet advertises 4700 MB/s write and 1950 MB/s read. The interface can handle more than 7000 MB/s in each direction. That's more than twice the advertised bandwidth of this drive.
If what you mean is that the MP600 isn't able to handle the claimed 4700 MB/s "most of the time" or something, than that's fair (I have no idea if that's the case or not). But the "interface" doesn't really come into play, here. The drive is advertised as PCIE 4.0 4x because the 3.0 revision couldn't handle the advertised maximum read specs.
Just like it would seem strange for an internet provider to sell a 400 Mbps (advertised) connection over a 100 Mbps line.
---
[0] https://en.wikipedia.org/wiki/PCI_Express#History_and_revisi...