As of now i own a Samsung 840 EVO 120GB SSD for my OS and such with me also owning a WD Black 1TB 7200 HDD. I am wanting to buy a new Storage device faster than my current one and is under $200. I do not care how much space it has just as long as it is enough for my OS like around 120GB atleast. I am really liking the Samsung 850 PRO SSD or maybe the Samsung M.2? What is the fastest storage i can get? I heard M.2 is the fastest.