We have an ageing MacBook Pro and I went on to the Apple forums to ask for help. Amongst the various suggestions included a recommendation for some utilities.
EtreCheck is a simple little app to display the important details of your system configuration and allow you to copy that information to the Clipboard. EtreCheck automatically removes any personally identifiable information from the output. EtreCheck does not need super-user privileges to run. It will also never ask for your password. It is signed with my Developer ID issued by Apple so it can be installed on systems protected by Apple’s Gatekeeper system.
FastTasks 2 – the troubleshooting app for your mac!
FT2 is a troubleshooting utility that provides a number of useful functions, including at-a-glance display of key system info, fast toggle of invisible files, free memory, remove login items and scan for troublesome apps and files.
FastTasks 2 uniquely allows you to keep logs of your system profile over time so you can easily see what changes were made to your system and when, a vital aid when things stop working as expected and you need to troubleshoot your mac.
FastTasks 2 is free.