Many Mac users like to keep a watchful eye on their system stats, including processor utilization, memory usage, disk activity, network usage, CPU temperature, fan speed, and perhaps battery stats. The Activity Monitor Dock icon offers one way to do this, but it’s on a limited basis, so if you’d rather see all kinds of system resource activity in a single control panel you may appreciate these two free Notification Center widgets for Mac OS X.
The first is called Monit, and once added to Notification Center it offers a means of quickly seeing an overview of CPU activity, memory usage, disk activity, battery, and network activity. You can then click on any of the little activity icons to get further information about each.
The second utility is called Fanny, and it keeps an eye on fan speed and CPU temperature of the Mac, also within Notification Center. This tool is likely most useful for Mac laptop users but many desktop users like to know what their fan is doing and what temperature the CPU is running.
Both of these utilities are installed as usual within Notification Center on the Mac, and after you have opened the individual app you can add the widget to Notification Center by opening the control panel, clicking on “Edit”, then adding the widgets and orientating them within the Notification Center panel as you see fit. You can also uninstall them at any time through the same Edit section of Notification Center.
These widgets are purely for monitoring general statistics and resource usage, there is no actionable PID list, so if you’re expecting to take action on a CPU hog by killing the app it won’t be done here and you’d need to rely on one of the various methods of force quitting a Mac app.
Do keep in mind that system activity monitoring uses a small amount of CPU itself, so if you’re really pinching for processor or resources you may not want to have these type of widgets going at all. And if you’re not the type to want to install third party tools or utilities, the top command line tool and Activity Monitor app can offer similar functionality without any add-ons in Mac OS X, which is great if you find Notification Center alerts to be annoying and the whole accompanying widget thing to be a nuisance or useless.