rockie_ :
Pro is faster but 840 EVO is fast enough . Even Crucial MX100 256+GB is awesome
http://anandtech.com/bench/product/1396?vs=1253
As for the better speed of pro, is the speed difference noticeable or very slight I have to know if it is worth the 30$ difference with the 850 evo or the 50$ difference with the 840 evo
The crucial seems like more a budget one but I dont wanna cheap out and and buy someone with 5 years guarantee with good read and write speed from a more trustable company like samsung or intel in this field...
So the 850 pro,850 evo,840 evo are the choises and im stuck..