Inert Detritus The Internet's dust bunnies

27 January 2008 @ 12pm

CPU History — An Activity Monitor Replacement

Today marks the release of my first application for Mac OS X: CPU History. CPU History is a 10.5‑compatible shameless ripoff of Apple’s original CPU Monitor, which I used in 10.2 to 10.4, but stopped working in 10.5.

CPU History is designed to do one thing, and do it well: graph your CPU usage history. It graphs the user, system, nice, and idle usage in the Dock icon, and optionally in a window which can be set to float above all others. CPU History lets you change the update frequency and the bar width, along with setting colors for each type of CPU usage.

Activity Monitor is a resource hog for this simple Dock icon graphing: between Activity Monitor and its pmTool background process, the two consumed 15–20% CPU on my iBook G4 in 10.5. By comparison, CPU History consumes 0.8–1.2%.

CPU History 1.0.1 is available over at its new home on, along with a git repository of the source code.

Much thanks to Bernhard Baehr and Peter Hosey for their applications, Memory Monitor and CPU Usage. Thanks to their source code, I was able to graft pieces of each onto the other and come up with a useful new application.


Posted by
9 February 2008 @ 8am

Could you provide a link to CPU History. I couldn’t find it at While I’m asking questions, will it graph each CPU on my new 8 core mac pro? That would be perfect. Activity Monitor doesn’t seem to.

Posted by
Christopher Bowns
10 February 2008 @ 11am

Sure thing, here’s the link.

As I’ve also noted on the main page, for the moment, it will only graph CPU 0. I’ve received a patch for multicore support, but I don’t know how well it’ll work with 8 cores. I’ll drop you an email when I get a full multicore compatible version working to get some feedback on it.