How is my RAM already full?
A few weeks ago I upgraded the RAM on my Early 2009 Macbook (white) from 2GB to 4GB because shortly after updating to Mavericks the fan just kept running all the time and the Activity Monitor showed my RAM was maxed out. For about 2 weeks or so everything was great and then it started acting like before. Now the fan just stays running and the Activity Monitor shows my 4GB is now maxed out as well. How in the world did this happen? I use a 1TB external hard drive for iPhoto and iTunes libraries already and I'm just confused as to what is going on. My internal 120GB hard drive says I have 63.48GB free. Any ideas why my fan is running all the time and how my RAM is maxed without me adding things? It's acting like a virus from my old PC days.
MacBook, Mac OS X (10.5.8)