You’re probably familiar with EtreCheck, the free app which is commonly used in Apple Community Support forums to help diagnose problems, but have you paid for its Pro features? If you want to get the best performance from your Mac, that’s money well-spent.

Among the additional features which are enabled when you make the in-app purchase is a superb graphical view of recently collected analytics data. Select the Performance item at the left (only enabled in the Pro version), scroll down until you reach the Analytics section, and click on the button to show the analytics chart.

There’s a great deal of information available here, covering the past few days of your Mac’s activities. Look particularly at the peaks of System and Total CPU shown in the lowest of the charts. Hover the pointer over one of the peaks and you’ll see a summary of the main processes using CPU cycles, and underneath that the time of that peak.

High CPU activity from one or more processes may be normal, or could represent a problem, such as a service which is in trouble and being restarted repeatedly. Although the processes listed here should give a general idea of what was loading the processor at the time, these analytics don’t tell you whether this was benign, or a problem which you could address. For that, we need to look at the log. Make a careful note of the time given for the peak, and open Ulbow.

There, ensure that the View menu is set to get Info messages and Signposts, that Limit entries shown is ticked, and to display log entries and Signposts. Then set up the controls at the top of the log window to obtain a log extract covering a period of around 5 minutes centred on the time of the peak seen in the analytics chart.

Here Ulbow is going to obtain a 5 minute period starting from 08:09:00, which would normally display tens of thousands of entries, far too many to browse. Click on the Get log button, and once the first thousand entries appear in the log extract window, open a Chart view using the command in the Window menu.

Ulbow will then show you a frequency chart of log entries within the chosen time period. Here it’s set to show all entries; use the popup to select a sub-system of interest to you. When you hover the pointer over a bar, a tooltip will appear giving the time for that group of log entries. Use those to navigate through other log excerpts, inspecting sub-systems of interest. You can determine whether the peaks shown in EtreCheckPro’s analytics coincide with problems manifesting themselves in log entries, or whether your Mac was just busy at the time.

Try doing that in Console.