I've had a poorly performing MBP i5 4GB 7200rpm machine. It's running slow as hell. Anyway, I've gone through the list: Before upgrading to 8GB of ram, I want to try reinstalling OS X. And if that doesn't work, good bye OS X and its poor memory management. If some scripts are causing the computer to run slowly, does that mean I should only copy over ~/Documents, ~/Movies, ~/Pictures, /Applications, ~/Music and not copy ~/. , ~/Application Support/ and /Application Support? I'm afraid if I copy over the config files, that could bring back the poor speed. Thanks.