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.