List of OS X components

How to Force Quit Applications on Your Mac When They’re Not Responding

Macs are very stable, but not every Mac application is. Every once in a while, something you’re using is going to crash. Sometimes this means the spinning beach ball of death, sometimes this means clicking an open window doesn’t do anything, no matter what you try. Sometimes the Dock indicates an application is open, but you can’t seem to find or open any windows.

Whatever’s gone wrong, clicking the red button or pressing Command+Q isn’t going to cut it. Here’s how to force zombie applications to quit, so you can re-launch them in a working state.

Force Quit an Application Using the Force Quit Menu

The simplest way to for an application to quit is the aptly named Force Quit tool, which you can find under the Apple logo in the menu bar. (You can also open this window by pressing Command+Option+Esc, which is like the Mac version of Ctrl+Alt+Delete.)

The Force Quit menu is a simple window, floating above all of your windows, with a list of currently running applications.

To force any application to close, click…

What Are mds and mdworker, and Why Are They Running on My Mac?

While checking out Activity Monitor, you noticed a couple of processes you don’t recognize: mds and mdworker. Neither have an icon, and they seem to be running constantly. Don’t worry, they’re harmless.

This article is part of our ongoing series explaining various processes found in Activity Monitor, like kernel_task, hidd, installd, and many others. Don’t know what those services are? Better start reading!

The two processes are part of Spotlight, the macOS search tool. The first, mds, stands for metadata server. This process manages the index used to give you quick search results. The second, mdworker, stands for metadata server worker. This does the hard work of actually indexing your files to make that quick searching possible.

Why Are mds and mdworker Using So Much RAM and CPU?

If you’ve recently migrated your files and apps from one Mac to another, it’s normal for mds and mdworker to take up a great deal of CPU power and memory. The same goes if you recently added a bunch of new files to your computer. The processes are both working to build an index of all…

What Is hidd, and Why Is It Running on my Mac?

You recognize most of the processes you see while browsing Activity Monitor, but not hidd. The name is cryptic, and there’s no icon for you to recognize. Should you be worried?

Absolutely not. The process called hidd is not harmful, and is actually part of macOS itself. The cryptic name stands for Human Interface Device Daemon. This daemon interprets all of your mouse movements and keyboard taps, meaning it’s essential if you want to use your Mac. Other input devices, such as tablets for drawing and game controllers, are also managed by this daemon.

It’s rare for hidd to cause problems, but it’s always possible. Here’s what to do if that happens.

What to Do if hidd Is Using Excessive System Resources

It’s rare, but occasionally Mac users report that hidd is using an excessive amount of…

What Is kernel_task, and Why Is It Running on my Mac?

So you found something called “kernel_task” in Activity Monitor, and you want to know what it is. Good news: it’s nothing nefarious. It’s actually your operating system.

A “kernel,” if you didn’t know, is at the core of any operating system, sitting between your CPU, memory, and other hardware and the software that you run. When your turn on your Mac, the kernel is the first thing that starts, and basically everything you do on your computer flows through the kernel at some point. Activity Monitor puts all of this varied activity under one banner: kernel_task.

If you’re computer isn’t running slowly, don’t worry about this process taking up a lot of memory or occasionally using up CPU cycles: that’s normal. Unused memory is wasted memory, so kernel_task will put it to work for things like caching files, and running a modern operating system means sometimes using some CPU power.

But if kernel_task is constantly using a majority of your system resources, and your Mac is really slow, you might have a problem. Restarting your Mac is the only way to restart your kernel, and sometimes that will solve all problems. But if the behavior persists, here’s a bit more information.

kernel_task Pretends to Use CPU Cycles To Keep Things Cool

If you’re doing something that takes up a lot of processing power—converting 4K videos, say—you might wonder what’s taking so long and look at the Activity Monitor. Often you’ll see kernel_task is using up a lot of CPU power…power which you’d rather that power be used by your intensive process.

It’s understandable if you’re frustrated, but it turns out your operating system is doing this on purpose to prevent your CPU from overheating. To quote Apple’s support page:

One of the functions of kernel_task is to help manage CPU temperature by making the CPU less available to processes that are using it intensely….