Chosen Solution
I know I’ll have a bottleneck, but it will be top speed anyway, and response times may be better too. I have a 250 GB SSD 850 Pro installed now, that’s giving me 380W and 510R. I should be able to get near 580 MB/s both W/R with the 950/960 SSD’s. What do you think? Will it work? Macbook Pro 13’ 2012 (9.2)
You need to focus in on the M.2 SSD’s specs. M.2 is a collection of different standards unlike SATA which was progressive each version getting faster but based on a common foundation. M.2 can be seen as two paths as you can see here in the diagram:
Sadly the SATA port in your system is a one trick pony it can’t support a PCIe/NVMe drive so your idea won’t work. I don’t even think the unibody series MacBook Pro’s (13’ or 15") chip set & OS can even support AHCI drives via the SATA port. Even still you would be limited to the SATA III (6.0 Gb/s) which would be 750 MB/s by the spec but still less due to the overhead. Then the devices true ability to fill that pipe still couldn’t achieve the full limit of the adjusted pipe So lets say 750 to 700 due to SATA dialog overhead, then adjusting the CRC Ack for each read/write at best 600 MB/s.
