Mac Emergency! Part 1: fast fixes for the most common Mac problems

Ted Landau
31 August, 2013
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System Slowdowns

It happens to every Mac user sooner or later. The virtual gears inside your computer begin to act as though they’re running in a vat of tapioca pudding. No matter what you try to do, your Mac moves at a pace that a snail could run circles around. Before carting the machine off to an Apple Genius Bar, try these fixes. BY TED LANDAU

Restart your Mac

One of the simplest steps you can take is also one of the most effective. Restarting your Mac cures most slowdowns, because it forces background processes to quit, frees up RAM and generally lets you begin afresh.

Check Network Preferences

For many Mac users, a slow internet connection is synonymous with a slow computer. That’s because almost everything they do – from surfing the web to checking email – requires internet access. If your online activity is moving at a crawl, improving your connection may be the cure.

Do you see a spinning beach ball in Safari when you try to load webpages? Initially it may be unclear whether pages are taking an unusually long time to load or whether your connection is broken. Select Apple menu > System Preferences > Network. Click Assist me > Diagnostics, pick your connection type and click Continue to run the tests. If a problem pops up, follow the Network Diagnostics tool’s advice for dealing with it.

Sick network. If Safari is slowing, check the health of your network connections.

Check your speed

Go to a site that tests internet connection speeds, if you can get the page to load. Options include and

You probably pay for certain upload and download speeds. Look at your bill or check with your ISP to see what those speeds are supposed to be. If you detect a slowdown, call the ISP to ask if it is experiencing general problems that may be affecting you. If so, you’ll have to wait for someone else to correct the issue. Alternatively, your ISP may offer to check and perhaps fix your modem connection through remote commands.

Test your Macs

If you have more than one Mac, test the internet speed on all of them. If the slowdown occurs on only one machine, the problem likely originates with that Mac. That system may, for instance, have an unusually weak Wi-Fi connection. If so, try simply turning your Wi-Fi off and then back on: go to the Wi-Fi menu in the menu bar and select Turn Wi-Fi Off. Wait a few seconds, and then turn it back on.

Disconnect and reconnect your modem

Unplug your internet modem, wait for about 10 seconds and plug it back in. If you have an AirPort Extreme or other separate router, do the same with it. Wait for everything to reboot. Check your speed again. (We’ll have some more suggestions in Part 2 soon.)

Check your disk usage with Activity Monitor

Remember, to run at a good pace, OS X must have adequate free space on the startup drive. If your Mac’s available disk space is near zero, the system will be sluggish.

One way to check the amount of free disk space on your Mac is to launch Activity Monitor (in the /Applications/ Utilities folder of OS X) and click the Disk Usage tab at the bottom. Our rule of thumb is that a system should have at least 10GB available (or 10 percent of the drive’s capacity, whichever is smaller). If your Mac’s free space falls below this threshold, you should clear some additional space.

Search for large files

An easy way to locate big files that you may no longer need is to use Spotlight. While you are in the Finder, press c-F, click the plus (+) sign, click the Kind pop-up menu, and select Other. Select File size from the resulting list, and then click OK. Set up the criterion to read File Size is greater than 500MB.

If nothing of consequence appears when you run that search, select a smaller file size and try again. Or try using a utility such as Id-design’s US$12.99 WhatSize ( Delete any files you no longer need.

Delete cache and log files

Ordinarily, cache files, such as those in the ~/Library/Caches folder, help your Mac run faster. If you delete them as a quick fix, your system will rebuild them later. Log files, such as those in the ~/Library/ Logs folder, keep track of past events on your Mac, including past crash reports. Most users never look at these files, so in all likelihood you can delete them without encountering any adverse consequences.

The simplest way to clean out your cache and log files is with a utility such as OnyX from Titanium Software (; donation requested). Launch OnyX and open the Cleaning tab. In your initial pass, delete only items in the User and Logs sections.

It’s possible that a bug, such as a ‘runaway’ log file, may be causing your drive to fill up much faster than it should. If the system’s available free space returns to near zero shortly after you clear the files, a bug of this type may be the culprit. If your Mac has this symptom, check the web for possible solutions.

Check your CPU usage

If your Mac’s central processing unit is overwhelmed by an app, everything on your system may slow down.

Launch Activity Monitor, and select My Processes from the pop-up menu near the top of the window. Click the % CPU column to sort by that criterion.

If an app consistently remains at or near the top of the % CPU list – and especially if it accounts for an atypically high percentage of the CPU’s workload (probably anything over 50 percent and certainly anything over 80 percent) – that program may be gumming up the works. To find out, select the app and click Quit Process.

The most likely source of such trouble, by far, is Apple’s Safari (and, more specifically, a webpage that contains Flash). If pages are loading extremely slowly, and if the % CPU figure for Safari and/or Safari Web Content remains high, it’s time for you to take action.

To reduce the odds that a Safari slowdown will recur, minimise the number of webpages that you keep open. You might also try using Google Chrome. If one tab misbehaves in Chrome, you can use Activity Monitor to zap it without bringing down the whole app.

Check virtual memory

Macs depend on a combination of physical memory and virtual memory to get things done. Virtual memory uses space on the Mac’s drive. Physical memory accesses installed RAM chips. Physical memory is faster.

The more heavily your Mac has to rely on virtual memory, the slower it will perform. Virtual memory also creates swapfiles that grow larger over time. (To find them, select Go > Go to Folder in the Finder, type /var/vm, and click Go.)

Swapfiles can contribute to a system slowdown by using up disk space, but you don’t need to delete them manually. Instead, go on to the next troubleshooting option…

Quit apps

To improve matters, quit apps that you aren’t currently using. Then restart your Mac. This action clears the swapfiles (among other things).

Check memory usage with Activity Monitor

As suggested above to investigate memory-usage problems, first launch Activity Monitor. Look under the column headers Real Mem and Virtual Mem. If an app is using a disproportionate amount of Real Mem and Virtual Mem, you can quit the app by selecting it in the list and clicking Quit Process.

We generally focus on the System Memory statistics at the bottom of Activity Monitor. (Click the System Memory tab to see these.) If the ‘Page outs’ and ‘Swap used’ values are high (over 2GB, as an approximation) and the amount of memory in the Free listing is approaching zero, insufficient memory is probably contributing to your slowdown.

Deal with persistent problems

When speed and memory problems remain, or soon reappear, one of two things may be responsible. First, the problem may be a ‘memory leak’ – a bug that causes a particular app to use excessive amounts of memory. Often a web search will confirm this situation and offer further advice. Second, your Mac may not have enough installed memory to meet your current needs.


If your Mac doesn’t already have its maximum amount of memory installed, and if its memory is accessible for upgrades, adding RAM is the quickest and cheapest way to give the system more zip.

See Apple’s system-specific guidelines for adding RAM to a MacBook Pro ( com/kb/HT1270), a MacBook (, an iMac ( HT1423), a Mac Pro (support. and a Mac mini ( com/kb/HT4432).

Get a bigger hard drive

If you continually bump up against your hard drive’s space limits, consider either replacing your current drive with a larger-capacity unit or offloading some of your files to an external drive. Shifting from a conventional hard drive to a solid-state drive can speed things up, too. The site iFixit ( contains useful step-by-step guides to replacing the hard drive on a variety of Mac models.

Buy a new Mac

If you can afford it – and especially if your Mac is more than three years old – your best bet might be to buy a new system.

A Mac several years newer than your current model is likely to have a faster processor, more memory, a larger and faster hard drive, faster ports (such as USB 3.0 in place of USB 2.0) and improved Wi-Fi performance. Add it all up, and it equals no more slowdowns, until the
cycle repeats in a few years.

Coming up tomorrow: the third part of Mac Emergencies: Part 1 will be ‘Mac won’t turn on’

by Ted Landau

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