Apple and macOS long ago became obsessed with reducing the power
usage on your Mac, through putting drives to sleep, dimming the
display, or going into sleep or hibernate modes. The original
reasons were practical: to avoid screen burn-in on a CRT, to reduce
wear on hard drives, to produce less heat, or simply to reduce
electrical usage for conservation and cost reasons.
We're in a post-CRT world with mostly efficient SSDs driving
Macs, and Apple silicon drops idle computers' heat profile and
electrical usage to a surprisingly low amount. Yet, Apple persists
in pushing for always using less juice. They're probably correct.
But what if you need your Mac to stay awake for a fixed period time
or for particular reasons?
You can use the menu
for a lot of straightforward operations, such as keeping your Mac
alert as long as a selected app remains running.
Open your eyes with Amphetamine, a free utility by William
Gustafson that lets you click, schedule, or trigger Mac alertness
from the menu bar. For such a simple concept as don't let parts or
all of a Mac go to sleep, Amphetamine has fleshed out a robust set
of options—and also lets you ignore them all.
In the simplest case, you can choose an item from the menu:
Indefinitely keeps your Mac awake until canceled, but you can also
select a duration, while a given app remains running, or until a
file is downloaded. (That last one is a neat treat: pick an
observation interval after which Amphetamine checks if the file has
changed in size so it can predict that the file has completed its
You can make things far more complicated, too. Let's say you
regularly plug in an external drive to a laptop to perform a Time
Machine backup or a drive clone, but you don't want to keep the
backup going if the battery runs low. In the app's preferences,
under Triggers, you can say as long as a given drive is mounted and
battery power is greater than 50 percent or the laptop is plugged
in, don't sleep.
A trigger lets you set
when Amphetamine keeps your Mac from sleeping.
Amphetamine has a lot of extras related to sleep behavior. The
Drive Alive preference lets you pick drives you never want to shift
into a state of inactivity—this matters only for hard drives, which
can have a spin-up time. Or you can let the app move your cursor at
intervals to simulate activity. There's a lot to explore and
configure when you need something other than default behavior.
Alternative icons let you avoid the drug association if
The name might seem to indicate being a little too wired, but
a lot of other names indicating wakefulness had already
been taken by its debut in 2014, which followed on from the
Caffeine app, no longer in development. If you don't like the
abstracted pill icon, you can select from a variety of others; I
picked a teapot. (Apple briefly blocked the app from the Mac App
Store in December 2020 because it allegedly appeared to promote
inappropriate use of controlled substances, but then
correctly reversed itself after a few days.)
Amphetamine answers the question, How do I keep my Mac awake
when I need it to be? with an essay-long response instead of
multiple choice. If you ever or regularly need your Mac to remain
constantly available, get this free app. And if that's useful to
you, help keep its developer alert by buying him
Macworld has never reviewed Amphetamine, but we did mention it in passing in March 2021 as
one of the greatest Mac apps [that] won't cost you anything more
than the time they take to download them.
Mac Gem is a column that highlight great nuggets of Mac
software, apps that have a high utility, have a sharp focus on a
limited set of problems to solve, and are generally developed by an
individual or small company. With the strong resurgence of the Mac
in recent years, we want to celebrate tools we use and that readers
recommend to make the most of your macOS experience. Stay tuned for
weekly updates, and send your suggestions to the Mac Gems Twitter