I have a laptop, a Toshiba Satellite C50-A and it has two RAM slots, one is used for a 4GB stick and the other is empty. My question is what RAM is compatible and is it still the case that the RAM has to match? As in it has to be two the same, I couldn't have the existing 4GB and then install either a 2GB or 8GB with it, could I? I've taken the existing 4GB stick out and took a photo of both sides of it, but this app on the iPhone won't allow me to add any pics. I'll try and reply to see if I can add the pics that way?