(Newbie warning) Sorry, what am I missing here? The Barefeats tests show cMPs PCIe 2.0 x4 card can do 5GB/s:
http://barefeats.com/hard220.html
No a 4 lane card cannot do 5GB/sec
https://en.m.wikipedia.org/wiki/PCI_Express
Actual throughput:
PCIe 2.0 1 lane: 500 MB/s
PCIe 2.0 4 lanes: 2 GB/s <- thunderbolt 2 and internal PCIe slot Apple put the SM951 on
PCIe 2.0 8 lanes: 4 GB/s
PCIe 2.0 16 lanes: 8 GB/s
Single Samsung SM951 read speed max: 2.091 GB/s.
PCI-e 3 / Thunderbolt 3, operates with a throughout just shy of 4GB/sec - still using 4 lanes.