What to do if your computer is slowing down

Updated 2018-08-08 …

With a new operating system on the horizon (Mojave), you might be thinking about ways to optimize and speed up your computer. Here’s a list of things that are always good to keep in mind.

Note: this is based on an article in Tech Tails #689, by Ed Shepard in 2012. It is interesting to see that the recomendations are still relevant in 2018.

Unfortunately, mysterious computer slowdowns can be difficult to diagnose. Overstuffed system cache, old temp files, corrupted preferences, a hard drive in the early stages of failure, and faulty RAM are always candidates for causing this problem. Here are some suggestions to resolve system slowdowns.

Important — make sure you have a solid backup of your Macs important data before proceeding.

Any Mac will slow down when its hard drive is almost full, regardless of processor speed. Simply moving some of your data (especially media files like movies, video podcasts, etc) to an external drive can greatly improve a Mac’s responsiveness.

Clear your Mac’s desktop. The OS has to draw each of those icons as separate windows, so when you have dozens of files littered on the desktop the system is taxed. Clearing the Macs desktop is proven to improve system performance.

Make sure your computer is up to date with all the latest software and firmware updates from Apple. This can go a long way to improving system performance. To check this, click the Apple in the top left corner of the screen and select “Software Update…”

Run a maintenance program such as Onyx or Clean My Mac. This can often help bring a sluggish and flakey machine back to speed. These programs force the Mac’s regular Unix maintenance scripts; normally these run daily, weekly, and monthly early in the morning.

Check the health of your hard drive. Run Onyx to verify the S.M.A.R.T. status of my Mac’s hard drive. Immediately back up your computer if you think there’s a real issue with the drive. Then consider using a dedicated drive diagnostic/repair tool such as Disk Warrior If the drive is having issues and you’re going to replace it, consider using a SSD drive. You will see a significant increase in processing speed.

Check the health of your Mac’s RAM. There are several ways to test the health of your Mac’s RAM. I use Rember, which is a free program that is a front-end GUI to a basic Unix ‘memtest’ command.

Remove unused applications. I use AppCleaner to do this.

Many apps install helper programs that run by default whenever you start up your Mac. This typically happens in the background, without the user having to confirm anything. Often these aren’t needed and can hog system resources without having anything to show for it. To disable startup items you don’t use, navigate to System Preferences > Accounts > Login items and uncheck the list.

Finally, any active, running application uses system resources including CPU cycles, RAM, and disk activity, even when it is in the background and you’re not using it. Some programs leak memory when they are running, which makes them gobble RAM over time.

Anaylyze system processes. Use Activity Monitor and iStat Menus to see which system processes and applications are hogging system resources.  Activity Monitor is found in the Applications/Utilities Folder in macOS.

Programs that automatically perform syncing, indexing and backup operations on your Mac can occasionally slow it down. They can sometimes cause minor drags that slow the system for a couple of seconds at a time.