M.2
http://tssdr1.thessdreview1.netdna-cdn.com/wp-content/uploads/2013/10/M.2-Comparison.jpg
https://upload.wikimedia.org/wikipedia/commons/thumb/e/ed/M2_Edge_Connector_Keying.svg/2000px-M2_Edge_Connector_Keying.svg.png
http://rog.asus.com/wp-content/uploads/2014/04/m.2-connectors.jpg
Socket 2（KeyB）Serial ATA/PCI Express x2 ※6pin独立
Socket 3（KeyM）Serial ATA/PCI Express x4 ※5pin独立
B+M keying maximize compatibility
http://akiba-pc.watch.impress.co.jp/img/ah/docs/651/074/mdosvp1407-232.jpg
http://www.techpowerup.com/img/16-06-05/74d.jpg
http://www.techpowerup.com/img/16-06-05/74b.jpg
http://www.techpowerup.com/img/16-06-05/81a.jpg