Activity Monitor Dock Icon

If you use the Activity Monitor app to check your CPU, memory, energy or disk use, you can hide the main app window and use the Dock icon to keep track of use. You can have the icon show CPU, disk or network usage in a little graph that updates continuously.
Video Transcript / Captions
Closed captioning for this video is available on YouTube: Activity Monitor Dock Icon.

You may already know about Activity Monitor. It's an app that's on your Mac that allows you to monitor CPU use, energy use, disk use on your Mac. Let's run it here. I'm going to use Spotlight so Command space, search for Activity Monitor and run it. You can see I get a list of processes. It's very technical. I can go to CPU use, Memory, Energy use, Disk use, Network use. I get graphs and things at the bottom. If you're a developer like myself it's somewhat useful. Typical Mac users don't really need it. But if you suspect a processor using a lot of power or battery on your MacBook you may want to monitor it and use this tool for that.

One of the really cool things about it is you don't have to have this big window open here all the time with this list of processes. It's pretty complex. You can instead use the Dock. I've got the Dock icon here for Activity Monitor and it's a static icon. But it doesn't have to be. You can actually set it to show you information.

For instance, I can, in Activity Monitor, go to View and there's a Dock Icon option here. I can say Show Disk Activity. I get a graph now that's going to continuously update showing me disk activity. It matches the graph shown here. So I can see here the Reads and Writes, blue for Reads and Red for Writes, and there's the graph in Activity Monitor and it's the same as in the Dock.

But I can hide Activity Monitor. Command H to hide or go to this menu here, Hide Activity Monitor. Now it's hidden and it doesn't get in my way but the icon still is there. I could also change to show other things. Like, for instance, I can do Network usage. That's going to spike when it's reading or writing to the internet various different things. So loading webpages, for instance, I would see a spike for Read.

I can also go to CPU history. That's going to give me a graph that's the same as this here and it's going to start at the beginning. So it's going to start building it up. So as I'm doing various things, maybe rendering video in Final Cut or audio on GarageBand, things like that, I'm going to see CPU use jump. Then lastly I've got an option for CPU use without the history. So it's just a little meter. So right now it's at the bottom but if I were to be using a lot of CPU it would jump up towards the top.

So this is really handy. You can Hide or Minimize the Activity Monitor and leave this down here. It has to be running. So if I Quit it's gone from the Dock. Even if I were to putt the Activity Monitor in the Dock by dragging it over to the left there, when I Quit it just goes back to the default icon. It has to be running to monitor these things and update it's Dock icon. But it's a handy little tool if you need to monitor your Mac's CPU use or some other use while you're working without having that big window getting in the way.