My Mac is Running Really Slow - Help!

This article will help you to diagnose common problems such as lack of maintenance, permissions conflicts and Hard Drive glitches that cause your Mac to run slowly.

There are two main routes to take to make your Mac as lean and mean as it was when you bought it (or even more so!)—hardware upgrades and software maintenance. One of the easiest things to do is to purchase additional RAM. As a rule, I say you can never have too much RAM. If you don't have at least 2GB of RAM, you should immediately upgrade. In addition to RAM, you should consider getting a faster hard drive (an SSD drive is what I recommend–more on that later). If your Mac is more than five years old, however, you might want to consider purchasing a new one, especially if you're running newer applications or the latest version of Mac OS X.

The following are essential utilities for keeping your Mac running smoothly and for fixing little problems that may crop up (Click the links to go to their download sites):

Running the Above Programs


OnyX is another free utility for running regular maintenance, although you must manually run this program's routines once a week or month (depending on your computer usage). One good thing about this utility, though, is that you can perform all the maintenance routines you'd need with one click in the Automation tab; after you do this, restart your Mac and see if everything's better.


Macaroni costs less than $10, but allows you to run all the necessary maintenance tasks automatically; it's kind of like combining both Anacron and OnyX, but Macaroni is easier to configure and use than both, and will make sure all the important maintenance tasks are run when the should be.

Monolingual Icon
Monolingual is a free utility that allows you to delete unused 'localization' files—files that allow your Mac to operate in many different languages; if you only live in one country and speak one language, you can free up a lot of hard drive space (sometimes more than 1 GB!) by deleting languages you don't use. Macaroni also performs this task.


Disk Utility comes installed on Mac OS 10.3 or later, and allows you to verify your hard disk or repair permissions by clicking on your hard drive and then clicking on the "Repair Disk Permissions" button.

Every Mac user should make sure he runs three basic maintenance tasks:

  1. 'Cron' scripts: Mac OS X is a UNIX operating system, and there are 'cron' scripts that clean up messy log files, optimize certain parts of the system, and accounts for user activity. There are three tasks - one that should be run daily, one weekly and one monthly. Anacron, OnyX, and Macaroni perform this task, but with newer Macs running 10.5 'Leopard' or later, this is no longer necessary to be run manually—your Mac takes care of it.
  2. Optimize Prebindings: Every time you install an application in Mac OS X, the installer will finish the installation by 'optimizing your system;' this is a fancy name for optimizing prebindings. Doing so will speed up application start times and keep things running smoothly. Macaroni does this.
  3. Repair Permissions: Because Mac OS X allows multiple user accounts, and because OS X has UNIX underpinnings, file 'permissions' can become messed up sometimes, especially if you have many different users on your computer, and they use the same programs. Sometimes, really weird things can happen as a result of your permissions being messed up, and this can also slow down your computer. OnyX, Macaroni and Disk Utility perform this task.

One last thing you can do that will not necessarily speed up your Mac, but will free up a considerable amount of hard drive space, is to erase the thousands of foreign language files that are installed with every application and utility on your computer. Sometimes, this can free up more than a gigabyte of hard drive space! Use Monolingual to do this.

Ways to Keep Your Mac Running Fast

In addition to using the above programs, you should keep in mind a few important things while using your computer to check email, install programs, browse the Internet or chat:

  1. Never open any attachments on emails that either you don't know who they're from or you don't already know what is in the attachment. Some malicious software can even make an email look like it was sent to you from a friend or relative! Better to be safe than sorry.
  2. When installing new software, ALWAYS watch the installer and make sure you know what's being installed. Some programs will ask you if they can install additional software. This additional software is often unnecessary and can cause problems on your computer.
  3. If you chat, don't click on links sent to you by friends unless you are absolutely sure your friend intended to send you the link!
  4. Upgrade your computer's RAM (Click on the Apple Logo (top right of the screen) and choose "About This Mac" to see how much you currently have). The more RAM you have, the less your computer will have to access the hard drive to run programs (especially if you run more than one program at a time!). This might actually be the best thing you can do to speed up an old Mac. Newer Macs like MacBook Airs and Retina MacBook Pros don't allow you to upgrade the RAM after purchase, so make sure you buy the Mac with as much RAM as you can get!
  5. Make sure you have about 10-20% of your hard drive empty. Mac OS X automatically defragments most of your hard drive files, but it needs some free space so it can do this; plus, your computer will swap files with your RAM and hard drive to make certain programs run faster, so you need some free space for that. If your drive is almost full, you should consider getting a new drive; larger, faster drives can be very inexpensive when on sale at retailers such as Best Buy, Micro Center, Fry's and others.
  6. Keep your computer clean; if you have never opened your desktop computer and cleaned the dust from the inside, you should do so—you might be surprised at how much dust you find! You can use a Shop Vac and soft brush (keep static away, though!) or a can of compressed air (a few bucks at a computer store) to get rid of all the dust bunnies. Dust can cause a LOT of problems with a computer! Read more tips for cleaning iMacs, flat screen LCDs, iPods, and other Macs.

Other Notes & Addenda

Upgrading your Mac to a newer model is almost always the best way to increase performance... but, it can be pretty expensive. Instead of doing that, I typically recommend you consider:

  1. Upgrade your RAM
    I have said this twice already - it's the single most effective way to speed up your Mac (in almost every case). It's not too expensive. I have 12 GB in my work iMac, and the computer flies through most any task, even when I have 20-30 applications open!

    My recommendation: Buy RAM from Crucial specific to your computer from Amazon (for a great price).

  2. Upgrade your Hard Drive to an SSD (Solid State Disk)
    Doing this can make your Mac feel many times faster - especially when booting up, opening and closing applications, and waking/sleeping your Mac. I just bought a MacBook Air that has a slower processor than my other MacBook, but since it has a fast SSD, things like opening applications, switching between them, and browsing the web feel a LOT faster!

    Putting an SSD in your Mac will instantly make almost everything run multiple times faster—no matter how old your Mac is! 

    My recommendation: normally, a drive like the OCZ Agility 4 SSD would do well, and is pretty inexpensive.

    Don't take my word for it, though:

    1. An SSD in a 4-year-old MacBook
    2. SSD: Life in the Fast Lane
    3. Bare Feats Benchmarks for SSD drives

If you want to do this yourself, check this guide from Macworld (for upgrading your hard drive), or this guide from iFixIt (for upgrading RAM... or anything). If you want a professional to do it for you, you should check out Powerbook Medic (they repair all kinds of Macs).

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