I have an Alienware 15x from 2015 and currently running SAMSUNG SSD PM851 M.2 2280 128GB along with a 1TB drive. A search of product specs shows the SSD to be .... SATA Gen 3.0 – 6Gb/s (http://www.samsung.com/us/business/oem-solutions/pdfs/PM851-SSD-ProdOverview.pdf)

I am looking to upgrade my SSD to a 512GB preferably but 1TB will also be fine. I looked couple places and the same Samsung model in 512 gb is showing 3/5 star reviews. Anyone done any SSD upgrades and have recommendations for a good & reliable SSD?