For the most part OS X is very fast and nimble. However, with just a little bit of time and effort, you may find that you can get even more performance out of your mac. Try starting with these apps.
1. ATIccelerator II is an overclocking app for ATI based video cards. This app allows you to increase the clock speed, and thus increase performance of ATI based video cards on your Mac.
I recommend atMonitor to monitor GPU temps to insure your card doesn’t overheat after overclocking. If you see increased temps after overclocking, try installing smcFanControl to increase system fan speeds.
2. Xslimmer works by removing unnecessary bits of code from apps you have already installed on your mac. The slimming of the apps can often speed up launch time as well as recover gigabytes of hard drive space. (I saved 3.8GBs over the span of 28 apps)
3. Repair your permissions. Repairing permissions allows OS X to automatically fix errors which may have cropped up while installing various software on your system. Open Disk Utility and select the drive which houses your OS X installation. Click “Repair Disk Permissions”.
If your Mac is a bit on the older side, you may be able to eek a bit more performance if your not attached to the “Dashboard’. OS X’s Dashboard feature can consume upwards of 100MBs of RAM in addition to stealing some CPU performance. If your not using it everyday, try disabling it until you find you need it. Just paste this string of code into a terminal window. defaults write com.apple.dashboard mcx-disabled -boolean YES Press enter, then this killall Dock