Samsung 830 vs 840 pro for gaming

Hello, i need help figuring out if there is any difference between the Samsung 830 and 840 pro 256GB version for gaming will i see any differences in loading times for rpg/open world games between the 2 SSD's? like fallout games, elder scrolls (i will also install mods and such), gta and saints row, and other games like metro 2033, batman etc. i will be using the ssd as the boot drive, games and some software. i am getting a HDD later for other software and games.
this is the last thing in my future system built im getting before i order everything. here are my other components if interested.

COOLER MASTER Storm Stryker
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
ASUS P8Z77-V PRO
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
MSI N670 PE 2GD5/OC
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
CORSAIR Enthusiast Series TX650 V2 650W
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Intel Core i5-3570K
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
CORSAIR Vengeance 8GB
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Kingston HyperX KHX-FAN Fans
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
XIGMATEK Dark Knight II SD1283 Night Hawk Edition
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
SAMSUNG 830 or 840 Pro?????