UPDATE: Please also see How To Troubleshoot Your Mac with FT2.

There can be various reasons why your Mac starts running slowly. Some of these can be app-related – especially if you are making multiple changes in programs that have autosave enabled. Other problems could be due to running processor-heavy apps that need more RAM than you’ve presently got. Before you dash off to Crucial to check out your RAM upgrade options, here’s a few basics to run through:

1. Applications > Utilities > Disk Utility.app
How old is your HDD drive? Click on the top-most hard disk icon in the left column and check the S.M.A.R.T status at the bottom right of the window. Does it say ‘verified’? If it says anything else, back up all your important data and start thinking about buying a new hard disk. If the S.M.A.R.T status is verified, have a look at how much space you’ve got left. A nearly-full disk will slow you down. Generally, it is recommended that you have at least 10% free, but I’d work on getting that closer to 25% for optimum performance. If you have less than that, think about what can be archived onto a backup disk (or two..), such as photos, movies, and even your songs.

2. Applications > Utilities > Activity Monitor.app
What’s using all the CPU time? Is it something you need to be running? Select any obviously unnecessary resource hogs and hit ‘Quit Process’.

3.  > System Preferences > Users & Groups
How many apps are in your ‘Login Items’? Remove anything that is not absolutely necessary at start up time.

4. Have you downloaded MacKeeper or other Anti-virus software?
If so, remove it.

5. How recently did you upgrade to Lion and are you using Time Machine?
If you’ve only recently upgraded in the last day or so, or turned your Mac off not long after upgrading, perhaps Spotlight is still indexing (indicated by a dot in the middle of the ‘spyglass’, top right of your screen) or TM is still updating (indicated by the TM indicator spinning in the menubar). Either or these will eventually finish and return your system to (about) normal, but you should let your system run (leaving it in ‘Sleep’ mode will do the trick) for at least 24 hours if you’ve only just upgraded.

6. Did you repair system permissions after upgrading?
Even though the Lion installer should fix system permissions after an upgrade, if you then added any other 3-rd party apps or restore something from Time Machine, repairing permissions is always a good idea. Doing so is harmless, and rules out permissions as a possible factor of poor performance. Do Step 4 here. Unless any are indicted in red type, don’t panic about the permissions errors that come up in the ‘details’ window – many of these can be safely ignored.

7. Clear out your caches
Caches, in general, help to speed your computer up. However, if you’re a heavy internet browser and you’ve never cleared your caches or your history (I mean like in several months), then this is worth doing from time to time. You can clean out Internet caches in Safari or Firefox by choosing Safari > Empty Cache or Firefox > Tools > Clear Recent History > Everything. Your computer has other caches that can usefully be cleared out periodically, too: use OnyX to do so.

8. Is the system slow with just one particular program or while trying to open some particular window?
A couple of things could be going on here. If its your browser, try killing some of those extensions/add-ons – every one of them slows you down just that little bit, and many slow you down a lot. Another possibility is a corrupt ‘plist’ or preference file associated with a particular app. Curing this is a bit more tricky and requires knowing your way around the hidden Library folder. If you think this is your problem, leave a comment below to get further instructions.

featured picture Speedo ©2011 Phil Stokes