I have a HP dm4-1165dx laptop (11 years old) and I am planning on upgrading from 4GB of RAM to 8GB. Should I get 2 new 4GB sticks or would it be okay if I used a new RAM stick with the stick that is 11 years old? (I should mention that if I were to combine old and new RAM, the brand/model of the new stick would be the same as the old one.)