memory upgrade help

hi i currently have 2 x 4gb sticks of corsair xms3 1600mhz. im looking at either getting another 2 sticks the same or completely replacing the ram all together. but not sure how much of an increase i would actually gain.

if replacing all together will make a reasonable difference what would you recommend?

https://www.overclockers.co.uk/cors...l-channel-kit-cmx8gx3m2a1600c9-my-290-cs.html

this is what i currently have

What do you use the PC for?

8Gb is fine for just gaming and some browsing.

Gaming starting to do some photo editing and benchmarking/ overclocking for fun