I have an older system, fx-8350, gtx 970, and at the moment just the 1 stick of 8 GB ram, see I have been playing assassin's creed odyessy at high settings averaging around 40 fps but now I'm playing assassin's creed origins and getting alot less fps which is weird as it is an older game, so i thought maybe it's best to try upgrade my ram to see if I get any advantages to hold me out till I completely upgrade my system in a few months time, when the new Ryzens come out.Much depends on game demands but 16GB may be of more advantage than it's frequency. 2 x 8GB of fast RAM in dual channel would surely bring some advantage.
Now we come to another problem, which RAM on which system do you have. Judging by 1600MHz, it makes me believe you have DDR3 memory and 2400MHz DDR3 is rarer than hen's teeth and expansive and unlikely your MB and CPU can take advantage of it.
Similar discussion here: https://forums.tomshardware.com/threads/is-ddr3-2400mhz-useless.1468804/