Question should i buy new ram or just add another stick

[SophieTheMeh]

i bought two new sticks of ddr4 memory when building my new rig (8gb total). Now if i was to upgrade to 16gb of ram would i buy two more sticks of the same ram i bought or replace the sticks i have now with two 8gb sticks?

 

[MrN1ce9uy]

The proper way is to replace them with a new kit of 2x8GB.