Basically what it says in the title.
I have a bit of spare cash lying around and was considering buying two more sticks of 4gb ram totalling 8gb which would bring my system up to 16gb in total.
I currently have two sticks placed in my Asrock Extreme6 in dual-channel mode but was basically wondering to avail of the two other dual channel slots do I need to purchase the exact same stick of ram down to the exact same model number.
Also on a side note, what kind of improvement will I see in terms of gaming and will it be noticeable?
As an example I play Skyrim on Ultra with a few settings dialled back a bit (shadows etc) with a huge amount of mods (texture mods,new lands and ENB enhanced shaders). With all this my FPS bounces around 30 to 50.
Will this added ram improve this situation (not that there is anything wrong with it)
You don't need the same ram, lthough its a good idea to prevent weird incompatibilities.
Your ram is 1600mhz with a cas latency of 9-9-9-24. Any ram with those specs should work perfectly.
Most games can only use 4-6gbs of system ram, so adding more will not help games at all. Toms has done a bunch of articles on this topic. More ram would be useful when running lots of programs at one time.
Before you buy the ram hit CTL+Alt+DEL and look at the performance tab on the windows task manager. It will show how much ram is being used.
Then play a game. You can alt tab out of the game and the task manager should still be running. You will see the usage drop as the game gets minimized, however the graph will show you were the memory usage was. I bet it never goes above 4.