I do not recommend the Samsung 951. The NMVE and the ACHI versions are both OEM drives. They were never meant for retail sales. They are meant to be used in off the shelf computer systems. Samsung has lucrative contracts to supply the OEM drives to companies like Dell, HP, Lenovo, and others. The drives may or may not have features that are inlcuded in retail versions. There are diffierent model and product numbers for each pc company. Each one may have slightly different features. In addition, there is no Samsung full factory warranty for the ssd. If something goes wrong you would have to contact the vendor instead of Samsung.
Instead of the 951, I recommend the 950 which is the retail version that comes with Samsung support and the Samsung full factory warranty.
There s still a problem. What are you trying to accomplish? How do you intend to use the ssd? What kind of PC do you have? Typically mainstream consumers and casual gamers use an ssd as a boot drive with the operating system installed on it.
I maintain an ssd database listed in a sticky at the very top of this forum section. Here is the link:
http://www.johnnylucky.org/data-storage/ssd-database.html
You can find the 950 and the 951 near the top of the database. Follow the links to the technical reviews. The links are divided into two categories - English language reviews and reviews in other languages.