I currently have an Acer Notebook-T5500..1gb Ram-Vista. I was going to add another GB of memory, but the best buy is out of the 1GB Dimms.. They only have the 2GB Dimms..so that would mean I have 1 GB Dimm in one and a 2GB in another..
I remember back in the day it was said that the computer may take a performance hit if the memory is not the same size..Is that still the case? Would be ok for me to combine a 1 GB Dimm with a 2 GB Dimm..I don't use the computer for any gaming..just HD Decoding and Office applications..
the right way is to makesure that the ram are same make and frequency, the best thing to do is takeout the ram in your laptop go to best buy and show it to them and yes buy 1 stick of 2gb the more the better. miximg brands will sometimes cause freezing ect..if you can't find the same one than replace everything and sell yours on ebay.
your maximum ram is 3gb to 3.5gb. don't go more thats if you have 2 slots underneath.