Hi all. I have a late 2007 macbook, that came with a 80GB hard drive and 1GB RAM. I have since upgrade it to a 160GB HD and 2GB RAM. My question is, what are the actual limits in terms of RAM? Im not struggling for HD space, but i do run some 3D rendering software from time to time and wondered how far i could take the RAM before it started causing any problems. Also, i understand my macbook won't support Mountain Lion because of the graphics issues, (Im currently on Snow Leopard still) is there any way to upgrade them? Many thanks.