Combining 4gb RAM with 8gb

[oliverbabic]

I have an ASUS zenbook that is compatible with 12 RAM. There is one 4 gb soldered to the motherboard and one slot with the other 4 gb (DDR3L 1600). My question is: can I replace the 4 gb with and 8 gb and get better performance? also: will they work together?

 

[Cycloid Torus]

Many RAM suppliers have 'look up' capabilities and you can check with them and order something which they 'guarantee'.
https://www.micron.com/
https://www.kingston.com/us