Once Activity Monitor is open, choose the CPU tab to sort processes by CPU percentage usage – this is basically showing you what processes or applications on the Mac are consuming processor, as a percentage of available CPU resources. Open Activity Monitor by opening Spotlight (Command+Spacebar) and typing “Activity Monitor” and then hitting the return key. This is somewhat advanced to take action on, but it’s simple enough to observe that it can be helpful. If a Mac feels slow or sluggish, one way to possibly find the culprit is to check Activity Monitor for processes that are using the slow down.

This is often the the number one reasons Mac users think a new operating system is slower than a prior version, so don’t disregard this simple advice! 2: Check CPU Use in Activity Monitor for Apps, Processes, etc When they’re finished, the performance of the Mac should be significantly better, if not entirely back to normal. So basically, let the Mac sit turned on overnight, perhaps for a few nights in a row, and allow those indexing and optimization processes to complete. I know that sounds like weird advice, but here’s the logic behind it: after a major macOS system software update, the Mac performs various maintenance routines behind the scenes, it reindexes the drive for Spotlight and Siri, and apps like Photos may reindex too. If you just recently updated to macOS Big Sur and you feel the Mac is slower than usual, the best course of action is to keep the Mac awake, plugged in (if it’s a laptop), and let it sit for a while (perhaps overnight or for a nights) – basically, hurry up and wait. 1: Slow Mac right after macOS Big Sur update? Wait it out!

Why is the Mac with Big Sur running slow? And what can you do about it? Let’s review a few of the possibilities and options to fix potential performance issues. We’ll walk through some possible reasons as to why macOS Big Sur feels slow on a Mac, as well as covering some advice and general tips and tricks to speed things back up again.

Mac running slow how to clean up