If you just recently upgraded to Mac OS Sierra and are experiencing a slowdown on your Mac, it could just be that you will have to wait out the sluggishness, as it will go away with time.
How to fix slow Sierra problems after upgrade?
Wait! That is the solution. Why do you have to wait? Because when you install a brand new OS or even a update for that matter, important tasks like Spotlight indexing take place on your Mac. What this means is that Spotlight is going to every nook and corner on your Mac to know where what is, to assist you quickly with future searches. This is mostly a one-time operation.
Depending on how much storage space and external drives are connected to your Mac, Spotlight can be an extremely busy process, sometimes using up even 70% of your available RAM. When 70% of RAM is being used by one process, you can imagine how slow your Mac can be when you attempt to do other things on it.
Take a look at your Mac’s activity monitor and see what activity is taking up your CPU and RAM resources. If it is Spotlight or Time Machine, you can relax as you know that these processes will abate with just a little time. In most cases, your Mac should be back to normal in 24 hours or less.
Try not to throw too many things at it during this time. Also, keep it plugged in so these resource hungry processes don’t stop abruptly because your Mac’s battery juice runs out.