Am idly considering the above. The laptop has 8GB on a single stick and I might add another 8GB. I've googled the model and its recommended some Crucial memory.

So the question is, I've seen comments about how memory sticks should be matched and should be as identical as possible, something to do with dual channel memory I think, so how similar do they need to be - do I really need to chuck out the existing memory and buy 16GB or can I just add an extra 8GB of the same spec memory ?