I just bought a new 11.6 inch i7 4gb ram macbook air and i can't help but notice how much ram it is always using. All i have opened is web browser and iTunes and it is sitting on 2.10 used ram. my old air would normally be at 1.4ish. Is this normal? I just downloaded sc2 and played it for an hour. Is playing such a graphically demanding game harmful for my macbook air? 