Questions I get lately, is that the mac is making a lot of noise. The Fans are spinning in high gear and OSX itself is slow. Responding slow.
There are some wise-ass answers like buy a new mac, but that is actually not nescecary in some cases. First look in activity of your system. Start the following app:
In my case the process “accountSD” was using about 500% of CPU. This process is used to check and handle all objects related to your account. Online and offline. But it appeared to be running in a loop. Solution, SMC and NV Ram reset!
For SMC you need to check which version of hardware you have. with or without T2 chip.