Greeting everyone, my PC have corsair dominator platinum ddr4 64gb 3000 c15, and planning to upgrade to 128gb. But I notice a difference for a set of 128gb and 2 sets of 64gb. The latency is difference. For 64gb, it is 15-17-17-35 and for 128gb, it is 16-18-18-36. What is the difference and will it affect the speed? The 128gb is way expensive than 2 sets of 64gb.

Thank You.

it's better to get another 64gb set with the same specs as your existing one.

I planning to get same another set of corsair dominator platinum 64gb and same spec. But the current setup of 128gb is different with the corsair 128gb set. Will it have big difference this 2?

theoretically mixed sets should work fine, but it's really for you to fine out, especially the stability part.