You’ll be amazed how snappy your ‘old’ Mac is when it’s starting on a pristine new disk.Ingredients After you’ve cleaned up all your redundant files, now it’s time to ‘sweep’ your disk.The quick and dirty answer is, if your Mac uses an Intel processor then you can upgrade to OS X 10.6 (Snow Leopard).However, there's much more you should know before you make a final decision.Can I upgrade or downgrade to Snow Leopard (OS X 10.6)?
We'll tackle the downgrade question a bit later in this guide.
Before you insert the Snow Leopard Install DVD into your Mac, take a bit of time to prepare your Mac for its new OS.
A little advance housekeeping will ensure a quick and uneventful installation.
Install Snow Leopard right on top of your existing Leopard install.
Apple recommends this, and in most cases it’ll be an easy, painless upgrade.