I bought a new laptop (HP 15-ac108nv). They said that it's a gaming laptop, anyway, i told them that i need to add one more 4gb ram (ddr3l) and they answered me that i have to buy a low voltage ram , so i decided to buy one from the internet , but i don't know how to recognize the low voltage ram. Low voltage means that is have to be up to 1333Mhz? I am so confused with all these , could you give me any advice what to do "add one more ram - it's not worth it"?