Different memory sizes?

[Jakefett98]

Hi, real quick question about RAM... I have a Dell Inspiron 15 3521 with 4gb ram. It has another slot, and I was wondering if it is ok to put my RAM from my old laptop (2gb) in the other slot... would that effect anything?

 

[Tradesman1]

If it will fit can try, no guarantees when mixing DRAM