I have an IMAC 20" bought in May 2009. I am operating a 10.6.8 system(snow leopard). 2 cores 2 GB memory2.66Ghz L2cache 6mb. My question is do I need more ram. When I first start my system memory is over a gb but very quickly drops to 500 or 400 or less free memory. I sometimes get a spinning wheel when I load some sites but not very often. If I do need more memory could you please suggest how and what I need. Thankyou so much.