How to choose an SSD for a new laptop

[NetLib]

I am trying to configure a new Dell Precision Mobile Workstation 7720 but the choices of SSD are daunting. They list a large number of choices such as:

• 
  - 512GB 2.5 inch SATA Solid State Drive
  - 512GB M.2 PCIe Solid State Drive Class 50
  - 512GB M.2 PCIe Solid State Drive Class 40
  - 512GB M.2 PCIe SED SSD Class 40
  - M.2 PCIe 512GB SED SSD Class 40 (with Interposer card drive)
  - and more

How do I make sense out of this for the fastest and most durable (best MTF)?

I could not find an article here about different SSD classes and types.

Thanks for any tips.

 

[CountMike]

M2 is your main clue, only requirement is that it has M2 connection, the rest is all about sizes and speed. Samsung 960 http://www.samsung.com/semiconductor/minisite/ssd/product/consumer/ssd960.html is quite fast.