i use ram drives etc, so went 16gb from the start, but unless your benchmarking there nobody alive who can notice the speed difference from one sort to another, more for me is always better than less, but i use the same rule of thumb on its better to have more slower ram than less quicker ram.
as your ram is really old mind you, just stick in what ever you can afford, but unless you are overclocking your cpu or memory and benchmark, you may or may not see any real life difference, in games it won't make one frame rate either way, neither in boot times etc, don't buy for the sake of it, buy because you want the upgrade, for me go 16gb of the cheapest if you can;t overclock what you already have, as 8 gb is fine for most.
8pack is a overclocking guru and maybe benchmarks all night and games less i don;t know, i benchmark once and game all the time and 1% either way makes little difference to me tbh.
he's god and i'm a nobody but for most games it matter little, your cpu maybe is abit slower with the ram you have, but great cpu anyway, so quicker memory would help, but will you see it in anything you play?
for me it all depends on your budget and how serious you play, for my games 16gb of the samsung greens would be fine, and i don;t overclock either, yes i did buy a bundle that was done for me as im old and idle, but i do like my games.
hopefully i have answered your query and not rambled too much
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