Time Machine on Mac

Is Time Machine taking forever to back up your Mac? You can speed it up temporarily with this Terminal trick.

If you are the type of Mac user that only backs up your data every once in a while (no judgement, everyone is different), you might have to wait a long time while Time Machine backs up all of the new stuff you've changed since the last backup. Reddit user villiansv discovered a Terminal trick that will disable the disk operation throttling mechanism, so Time Machine uses more CPU and backs up faster. Here's how.

What it means to speed up Time Machine and slow down other operations

The Terminal command used to speed up Time Machine essentially disables the program's throttling mechanism. It frees it up to gobble up CPU, and subsequently slow down the rest of your computer. If you were to forget to revert back to your original settings, you could really screw up your Mac's performance. It is essential that you follow the steps to revert back to your normal CPU activity.

A quote from Reddit user spasewalkr explains it better:

it's making a fundamental change to the way the kernel schedules disk operations, and prevents processes that are supposed to have low I/O priority from being properly throttled. Forgetting to undo this setting could have serious implications for battery life, could impact the performance of games or other high-demand processes since they're now competing for resources, or could have other non-obvious negative consequences.

How to speed up Time Machine so it backs up your data faster

Disabling the throttling feature of disk operations

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

How to revert to your normal CPU activity

Enabling the throttling feature of disk operations

While it may be super awesome to speed up your Time Machine backup, it is doing so at the expense of everything else. You don't want the throttle disabled at all times. After you've finished backing up your data, you'll want to revert to having Time Machine run quietly and slowly in the background (or not at all if you're not running it constantly). Use this Terminal command to reenable the CPU throttle.

sudo sysctl debug.lowpri_throttle_enabled=1

Any questions?

Do you have any questions about disabling the throttling mechanism, freeing Time Machine up to run faster? Put them in the comments! Also, don't forget to enable the throttle again after you're done!