I am doing a lot of research and working with pdf files that are over 10GB big and tons of pictures, like about 3000 that I use apertures to sort out etc. 4GB was not cutting and frequelnty iStat would tell me I have 0 free ram. My system would screech to a halt and it became very slow and unresponsive. I would run the preview app(8GB file) aperture with about 3000 pictures) and chrome with 6-8 tabs open at a time. So I decided to upgrade to 8GB ram and I still get the unresponsiveness and slowness I was experiencing. I bought the 8GB kingston RAM in hopes of buying brand name brings good performance. iStat tell me I have about 2GB of free memory and fluctuates around there. For my type of work, should I go back to 4GB and get a SSD? It seems I need the memory. Or maybe I just have bad performaing RAM? Buy another brand? Im a little stuck here. I have a core i5 15 inch 2.4 base model.