If you are a constant-on Time Machine user, you won’t even notice when a scheduled backup is taking place. That’s because Time Machine is designed to work quietly and slowly in the background. Most of your regular backups are incremental and therefore don’t need much power. If you only back up your Mac once per week (or longer), Time Machine has a lot more work to do, but still runs quietly and slowly in the background. Using this Terminal command, you will disable the disk operation throttling so Time Machine will run faster.
sudo sysctl debug.lowpri\_throttle_enabled=0
Restore default setup:
sudo sysctl debug.lowpri\_throttle_enabled=1