I recently upgraded from a mid 2009 13" cMBP (with a liquid damaged keyboard) to a refurbished base 2012 15" cMBP off the Apple website. I'm really happy with the laptop, especially having a working keyboard and power button . In general it's been a big improvement, especially gaming in boot camp. However, in my general day to day usage on OS X, it often feels slower than my old one. I often get beachballs for a few seconds at a time, especially in Safari. Otherwise it just feels a bit stuttery sometimes. Old specs: 13" mid 2009 C2D 2.26 Ghz 8GB RAM aftermarket 500GB 7200rpm WD Scorpio Black aftermarket Nvidia 9400m New specs: 15" mid 2012 non-retina i7 QC 2.3 Ghz 4GB RAM 500GB 5400rpm stock Nvidia GT 650m 512mb + HD 4000 I have a feeling it might be the RAM, but wondered if there was anything else that might be a problem. In my typical OS X usage I leave the following open at the same time: Safari with roughly 5-10 tabs Mail iTunes Steam often preview with a pdf or two To me it seems like 4GB would be enough for this. On top of those I sometimes run guitar amp/effects modelling software and/or GarageBand. Is the decreased RAM the likely culprit for slower performance, or could there be something else going on? I don't want to just upgrade the RAM if it wont make much of a difference, especially considering 8GB costs more than when I upgraded my old one in 2011. Edit: Typical RAM usage from activity monitor has a small sliver of free, with roughly a third between wired, active and inactive. I've never completely understood if inactive can should be thought of as used or unused.