ChromeOS

Google is preparing a way to hibernate your Chromebook to help save power

Kyle Bradshaw | Feb 1 2022 - 8:56 am PT

It will soon be possible to hibernate your Chromebook instead of simply putting it to sleep, allowing it to conserve even more battery while not in use.

When you close your Chromebook or walk away from it for an extended period of time, it will go into a “sleep” state, which pauses the operating system and turns off unnecessary uses of power. One thing that will stay running, though, is your RAM, which holds the data of your currently running programs and Chrome tabs — one might say especially your Chrome tabs.

For short periods, such as simply closing the Chromebook before your commute, this is efficient as you can re-open your Chromebook and be precisely where you left off in seconds, if not instantly. But if you leave your Chromebook unused for a few days or longer, you’ll find that your battery has been drained, from the RAM still being powered.

Unlike most other operating systems, your only other option is to completely power off your Chromebook. This will absolutely conserve power, but it comes at the cost of restarting your apps and reopening your tabs/windows. Modern hardware has made restarting your computer much faster, but this will always be the slowest route.

Meanwhile, most operating systems offer the option to “hibernate” your device. Hibernation acts as a compromise between the two routes by taking the information in your RAM, backing it up to your storage, and shutting down the computer. You get the power saving benefits of being shut down and the speed boost of everything being right where you left it, at the cost of not being quite as fast as sleep mode.

Thus far, Chrome OS has not offered hibernation, despite being based on Linux which does have its own hibernation feature built into the kernel. This is changing in the near future, as part of an effort that started at least as far back as October of last year to introduce “Hiberman,” Chrome OS’s own hibernation manager (get it? hiber-man).

Google has publicly laid out the details of how hibernation will operate in Chrome OS, and it’s a fascinating read for those interested in how operating systems work. For everyone, though, the key takeaway is actually the core way in which Hiberman is different from Linux’s version of hibernation. Specifically, the data being saved from your RAM will be encrypted before it’s written to your disk.

For the average person who isn’t at risk of having their laptop stolen and rifled through for information, this isn’t necessarily a meaningful benefit, but it should offer a greater overall sense of security. Relatedly, if you hibernate your Chromebook and someone besides you logs into the device next, your session is deleted, for security’s sake among other reasons.

It’s not clear at this time how you’ll choose to hibernate your Chromebook — the most obvious choice being a new option in the power menu — but the flow for powering back on is straightforward. When booting up from hibernation, your Chromebook will notice the saved data — checking it first to make sure it hasn’t been tampered with — ask you to log in, and then decrypt and load the data back into RAM.

One currently unanswered question is how long the hibernation and waking process will take. Now that Hiberman has moved further along in development, Googlers will soon begin testing to see how long it will take. According to a comment from the feature’s lead developer, the current hope is that “in the majority of cases” the wait time between signing in and having your data fully decrypted is “pretty short.”

As for when we can expect Chromebooks to begin offering hibernation, considering testing is only just beginning, we’re likely still a few months away from launch.