Buying another 2x4gb kit or a single 4gb stick to upgrade

Robert-

Reputable
Jun 20, 2015
55
0
4,640
I have 8gbs of HyperX Fury ram in 2 4gb sticks. I want to upgrade to 16, will there be no problems at all buying the exact same set again so I have 4 sticks?

If I wanted to just buy a 4gb stick to bring me up to 12 would that cause any issues? And then probably buy another 4 in the future.